From 400519cd95327561b00fbc7d150b864bb0602c05 Mon Sep 17 00:00:00 2001
From: Gaurav Dnyandeo Kukade <gkukade54@gmail.com>
Date: Sun, 3 Jan 2021 16:18:44 +0530
Subject: [PATCH 01/31] Update README.md

---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 09cce52..77eb236 100644
--- a/README.md
+++ b/README.md
@@ -1 +1 @@
-#Visit coderolls.com
\ No newline at end of file
+# Visit coderolls.com

From 9df32786626a66c2b9219ab3cbc2459032e9ea25 Mon Sep 17 00:00:00 2001
From: Gaurav Dnyandeo Kukade <gkukade54@gmail.com>
Date: Sun, 3 Jan 2021 16:19:04 +0530
Subject: [PATCH 02/31] Update README.md

---
 java-files-io/README.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/java-files-io/README.md b/java-files-io/README.md
index e4d01b2..a75de73 100644
--- a/java-files-io/README.md
+++ b/java-files-io/README.md
@@ -1,3 +1,3 @@
-#coderolls Files IO Tutorials
+# coderolls Files IO Tutorials
 
-1. [How To Read File Using BufferedReader In Java?](https://coderolls.com/read-file-using-bufferedreader/)
\ No newline at end of file
+1. [How To Read File Using BufferedReader In Java?](https://coderolls.com/read-file-using-bufferedreader/)

From 327c5cc5f4e17cc8317bbe5fde7a0682fc42837c Mon Sep 17 00:00:00 2001
From: Gaurav <gkukade54@gmail.com>
Date: Sat, 9 Jan 2021 10:56:40 +0530
Subject: [PATCH 03/31] Add examples for How to parse json in java blog

---
 .../ParseJSONUsingGSON.java                   | 68 +++++++++++++++++
 .../ParseJSONUsingJSONJava.java               | 67 +++++++++++++++++
 .../ParseJSONUsingJsonSimple.java             | 73 +++++++++++++++++++
 java-json/parse-json-in-java/pom.xml          | 43 +++++++++++
 4 files changed, 251 insertions(+)
 create mode 100644 java-json/parse-json-in-java/ParseJSONUsingGSON.java
 create mode 100644 java-json/parse-json-in-java/ParseJSONUsingJSONJava.java
 create mode 100644 java-json/parse-json-in-java/ParseJSONUsingJsonSimple.java
 create mode 100644 java-json/parse-json-in-java/pom.xml

diff --git a/java-json/parse-json-in-java/ParseJSONUsingGSON.java b/java-json/parse-json-in-java/ParseJSONUsingGSON.java
new file mode 100644
index 0000000..0322ce2
--- /dev/null
+++ b/java-json/parse-json-in-java/ParseJSONUsingGSON.java
@@ -0,0 +1,68 @@
+package com.coderolls.JSONExample;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonObject;
+
+/**
+ * A program to parse JSON strin in Java using Gson
+ * @author Gaurav Kukade at coderolls.com
+ */
+
+public class ParseJSONUsingGSON {
+
+	public static void main(String[] args) {
+
+		//take json as string
+		String jsonString = "{"
+				+ "  \"name\": \"coderolls\","
+				+ "  \"type\": \"blog\","
+				+ "  \"address\": {"
+				+ "    \"street\": \"1600 Pennsylvania Avenue NW\","
+				+ "    \"city\": \"Washington\","
+				+ "    \"state\": \"DC\""
+				+ "  },"
+				+ "  \"employees\": ["
+				+ "    {"
+				+ "      \"firstName\": \"John\","
+				+ "      \"lastName\": \"Doe\""
+				+ "    },"
+				+ "    {"
+				+ "      \"firstName\": \"Anna\","
+				+ "      \"lastName\": \"Smith\""
+				+ "    },"
+				+ "    {"
+				+ "      \"firstName\": \"Peter\","
+				+ "      \"lastName\": \"Jones\""
+				+ "    }"
+				+ "  ]"
+				+ "}";
+		
+		System.out.println("Parsing the json string in java using Gson......\n");
+		Gson gson = new Gson();
+		
+		//get json object from the json string
+		JsonObject coderollsJsonObject = gson.fromJson(jsonString, JsonObject.class);
+		
+		//now we can access the values 
+		String name = coderollsJsonObject.get("name").getAsString();
+		System.out.println("Name: "+name+"\n");
+		
+		//we can get the JSON object present as value of any key in the parent JSON
+		JsonObject addressJsonObject = coderollsJsonObject.get("address").getAsJsonObject();
+		
+		//access the values of the addressJSONObject 
+		String street = addressJsonObject.get("street").getAsString();
+		System.out.println("Street: "+street+"\n");
+		
+		
+		//we can get the json array present as value of any key in the parent JSON
+		JsonArray employeesJsonArray = coderollsJsonObject.get("employees").getAsJsonArray();
+		System.out.println("Printing the employess json array: \n"+employeesJsonArray.toString()+"\n");
+		
+		//we can get individual json object at an index from the employeesJSONArray
+		JsonObject employeeJsonObject = employeesJsonArray.get(0).getAsJsonObject();
+		String firstName = employeeJsonObject.get("firstName").getAsString();
+		System.out.println("First Name of the employee at index 0: "+firstName);
+	}
+}
diff --git a/java-json/parse-json-in-java/ParseJSONUsingJSONJava.java b/java-json/parse-json-in-java/ParseJSONUsingJSONJava.java
new file mode 100644
index 0000000..48de8e0
--- /dev/null
+++ b/java-json/parse-json-in-java/ParseJSONUsingJSONJava.java
@@ -0,0 +1,67 @@
+package com.coderolls.JSONExample;
+
+import org.json.JSONArray;
+import org.json.JSONObject;
+
+/**
+ * A program to parse JSON strin in Java using json-simple
+ * @author Gaurav Kukade at coderolls.com
+ */
+
+public class ParseJSONUsingJSONJava {
+
+	public static void main(String[] args) {
+		
+		//take json as string
+		String jsonString = "{"
+				+ "  \"name\": \"coderolls\","
+				+ "  \"type\": \"blog\","
+				+ "  \"address\": {"
+				+ "    \"street\": \"1600 Pennsylvania Avenue NW\","
+				+ "    \"city\": \"Washington\","
+				+ "    \"state\": \"DC\""
+				+ "  },"
+				+ "  \"employees\": ["
+				+ "    {"
+				+ "      \"firstName\": \"John\","
+				+ "      \"lastName\": \"Doe\""
+				+ "    },"
+				+ "    {"
+				+ "      \"firstName\": \"Anna\","
+				+ "      \"lastName\": \"Smith\""
+				+ "    },"
+				+ "    {"
+				+ "      \"firstName\": \"Peter\","
+				+ "      \"lastName\": \"Jones\""
+				+ "    }"
+				+ "  ]"
+				+ "}";
+		
+		System.out.println("Parsing the json string in java using JSON-Java......\n");
+
+		//add jsonString to the constructor
+		JSONObject coderollsJSONObject = new JSONObject(jsonString);
+		
+		//now we can access the values 
+		String name = coderollsJSONObject.getString("name");
+		System.out.println("Name: "+name+"\n");
+		
+		//we can get the JSON object present as value of any key in the parent JSON
+		JSONObject addressJSONObject = coderollsJSONObject.getJSONObject("address");
+		
+		//access the values of the addressJSONObject 
+		String street = addressJSONObject.getString("street");
+		System.out.println("Street: "+street+"\n");
+		
+		
+		//we can get the json array present as value of any key in the parent JSON
+		JSONArray employeesJSONArray = coderollsJSONObject.getJSONArray("employees");
+		System.out.println("Printing the employess json array: \n"+employeesJSONArray.toString()+"\n");
+		
+		//we can get individual json object at an index from the employeesJSONArray
+		JSONObject employeeJSONObject = employeesJSONArray.getJSONObject(0);
+		String firstName = employeeJSONObject.getString("firstName");
+		System.out.println("First Name of the employee at index 0: "+firstName);
+	}
+
+}
diff --git a/java-json/parse-json-in-java/ParseJSONUsingJsonSimple.java b/java-json/parse-json-in-java/ParseJSONUsingJsonSimple.java
new file mode 100644
index 0000000..5c3e2e2
--- /dev/null
+++ b/java-json/parse-json-in-java/ParseJSONUsingJsonSimple.java
@@ -0,0 +1,73 @@
+package com.coderolls.JSONExample;
+
+import org.json.simple.JSONArray;
+import org.json.simple.JSONObject;
+import org.json.simple.parser.JSONParser;
+import org.json.simple.parser.ParseException;
+
+/**
+ * A program to parse JSON strin in Java using json-simple
+ * @author Gaurav Kukade at coderolls.com
+ */
+
+public class ParseJSONUsingJsonSimple {
+
+	public static void main(String[] args) {
+		//take json as string
+		String jsonString = "{"
+						+ "  \"name\": \"coderolls\","
+						+ "  \"type\": \"blog\","
+						+ "  \"address\": {"
+						+ "    \"street\": \"1600 Pennsylvania Avenue NW\","
+						+ "    \"city\": \"Washington\","
+						+ "    \"state\": \"DC\""
+						+ "  },"
+						+ "  \"employees\": ["
+						+ "    {"
+						+ "      \"firstName\": \"John\","
+						+ "      \"lastName\": \"Doe\""
+						+ "    },"
+						+ "    {"
+						+ "      \"firstName\": \"Anna\","
+						+ "      \"lastName\": \"Smith\""
+						+ "    },"
+						+ "    {"
+						+ "      \"firstName\": \"Peter\","
+						+ "      \"lastName\": \"Jones\""
+						+ "    }"
+						+ "  ]"
+						+ "}";
+				
+		System.out.println("Parsing the json string in java using json-simple......\n");
+		
+		JSONParser parser = new JSONParser();
+		JSONObject coderollsJSONObject = new JSONObject();
+		try {
+			coderollsJSONObject = (JSONObject) parser.parse(jsonString);
+		} catch (ParseException e) {
+			e.printStackTrace();
+		}
+		
+		//now we can access the values 
+		String name = (String) coderollsJSONObject.get("name");
+		System.out.println("Name: "+name+"\n");
+		
+		//we can get the JSON object present as value of any key in the parent JSON
+		JSONObject addressJSONObject = (JSONObject) coderollsJSONObject.get("address");
+		
+		//access the values of the addressJSONObject 
+		String street = (String) addressJSONObject.get("street");
+		System.out.println("Street: "+street+"\n");
+		
+		
+		//we can get the json array present as value of any key in the parent JSON
+		JSONArray employeesJSONArray = (JSONArray) coderollsJSONObject.get("employees");
+		System.out.println("Printing the employess json array: \n"+employeesJSONArray.toString()+"\n");
+		
+		//we can get individual json object at an index from the employeesJSONArray
+		JSONObject employeeJSONObject = (JSONObject) employeesJSONArray.get(0);
+		String firstName = (String) employeeJSONObject.get("firstName");
+		System.out.println("First Name of the employee at index 0: "+firstName);
+	}
+
+}
diff --git a/java-json/parse-json-in-java/pom.xml b/java-json/parse-json-in-java/pom.xml
new file mode 100644
index 0000000..3bcf581
--- /dev/null
+++ b/java-json/parse-json-in-java/pom.xml
@@ -0,0 +1,43 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>com.coderolls</groupId>
+  <artifactId>JSONExample</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+  <packaging>jar</packaging>
+
+  <name>JSONExample</name>
+  <url>http://maven.apache.org</url>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>3.8.1</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+	    <groupId>org.json</groupId>
+	    <artifactId>json</artifactId>
+	    <version>20201115</version>
+	</dependency>
+	<dependency>
+	    <groupId>com.google.code.gson</groupId>
+	    <artifactId>gson</artifactId>
+    	<version>2.8.6</version>
+	</dependency>
+	
+	<!-- https://mvnrepository.com/artifact/com.googlecode.json-simple/json-simple -->
+	<dependency>
+	    <groupId>com.googlecode.json-simple</groupId>
+	    <artifactId>json-simple</artifactId>
+	    <version>1.1.1</version>
+	</dependency>
+	
+  </dependencies>
+</project>

From 193d7b9961910beb5be80487822ea39d210d6419 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Fri, 5 Mar 2021 00:22:24 +0530
Subject: [PATCH 04/31] Add java programs to convert double to int in java

---
 .../DoubleToIntUsingIntValueMethod.java       | 25 ++++++++++++++
 java-basic/DoubleToIntUsingRoundMethod.java   | 34 +++++++++++++++++++
 java-basic/DoubleToIntUsingTypecasting.java   | 18 ++++++++++
 3 files changed, 77 insertions(+)
 create mode 100644 java-basic/DoubleToIntUsingIntValueMethod.java
 create mode 100644 java-basic/DoubleToIntUsingRoundMethod.java
 create mode 100644 java-basic/DoubleToIntUsingTypecasting.java

diff --git a/java-basic/DoubleToIntUsingIntValueMethod.java b/java-basic/DoubleToIntUsingIntValueMethod.java
new file mode 100644
index 0000000..09f28a5
--- /dev/null
+++ b/java-basic/DoubleToIntUsingIntValueMethod.java
@@ -0,0 +1,25 @@
+/**
+ * 
+ * A java program to convert double to int using 
+ * Double.intValue() method  
+ * @author Gaurav Kukade at coderolls.com
+ * 
+ **/
+public class DoubleToIntUsingIntValueMethod{
+
+     public static void main(String []args){
+
+        double doubleValue = 82.14; // 82.14
+        
+        System.out.println("doubleValue: "+doubleValue);
+        
+        //create Double wrapper object
+        Double doubleValueObject = new Double(doubleValue);
+        
+        
+        //typecase double to int
+        int intValue = doubleValueObject.intValue(); // 82
+        
+        System.out.println("intValue: "+intValue);
+     }
+}
diff --git a/java-basic/DoubleToIntUsingRoundMethod.java b/java-basic/DoubleToIntUsingRoundMethod.java
new file mode 100644
index 0000000..44df81f
--- /dev/null
+++ b/java-basic/DoubleToIntUsingRoundMethod.java
@@ -0,0 +1,34 @@
+/** 
+ * A java program to convert double to int using 
+ * Math.round() method 
+ * @author Gaurav Kukade at coderolls.com
+ **/
+public class DoubleToIntUsingRoundMethod{
+
+     public static void main(String []args){
+        
+        // case 1
+        double doubleValue = 82.14; // 82.14
+        
+        System.out.println("doubleValue: "+doubleValue);
+        
+        //typecase double to int
+        int intValue = (int) Math.round(doubleValue); // 82
+        
+        System.out.println("intValue: "+intValue);
+        
+        System.out.println();
+        
+        // case 2
+        double nextDoubleValue = 82.99; // 
+
+        
+        System.out.println("nextDoubleValue: "+nextDoubleValue);
+        
+        // Math.round(nextDoubleValue) returns long value
+        //typecase long to int
+        int nextIntValue = (int) Math.round(nextDoubleValue); // 83
+        
+        System.out.println("nextIntValue: "+nextIntValue);              
+     }
+}
diff --git a/java-basic/DoubleToIntUsingTypecasting.java b/java-basic/DoubleToIntUsingTypecasting.java
new file mode 100644
index 0000000..8287654
--- /dev/null
+++ b/java-basic/DoubleToIntUsingTypecasting.java
@@ -0,0 +1,18 @@
+/**
+ * A java program to convert double to int using typecasting 
+ * @author Gaurav Kukade at coderolls.com
+ **/
+public class DoubleToIntUsingTypecasting{
+
+     public static void main(String []args){
+        
+        double doubleValue = 82.14; // 82.14
+        
+        System.out.println("doubleValue: "+doubleValue);
+        
+        //typecase double to int
+        int intValue = (int) doubleValue; // 82
+        
+        System.out.println("intValue: "+intValue);
+     }
+}

From 128680863ca3e9adcdaa3d2fb0ec9eb72c8b8e34 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Sun, 5 Dec 2021 10:01:02 +0530
Subject: [PATCH 05/31] Add arraylist java programs

---
 collections/arraylist/README.md               | 14 +++++
 .../ArrayListAddExample.java                  | 33 ++++++++++++
 .../ArrayListExample.java                     | 34 ++++++++++++
 .../arraylist-in-java/ArrayListDuplicate.java | 20 +++++++
 .../arraylist-in-java/ArrayListExample.java   | 26 ++++++++++
 .../ArrayListSetExample.java                  | 34 ++++++++++++
 .../ArrayListIterateExample1.java             | 33 ++++++++++++
 .../ArrayListIterateExample2.java             | 34 ++++++++++++
 .../ArrayListIterateExample3.java             | 36 +++++++++++++
 .../ArrayListIterateExample4.java             | 41 +++++++++++++++
 .../ArrayListIterateExample5.java             | 32 ++++++++++++
 .../ArrayListRemoveExample.java               | 30 +++++++++++
 .../ArrayListRemoveExample2.java              | 32 ++++++++++++
 .../ArrayListRemoveObjectExample.java         | 35 +++++++++++++
 .../ArrayListRemoveObjectExample2.java        | 36 +++++++++++++
 .../Employee.java                             | 52 +++++++++++++++++++
 16 files changed, 522 insertions(+)
 create mode 100644 collections/arraylist/README.md
 create mode 100644 collections/arraylist/add-element-in-arraylist/ArrayListAddExample.java
 create mode 100644 collections/arraylist/add-element-in-arraylist/ArrayListExample.java
 create mode 100644 collections/arraylist/arraylist-in-java/ArrayListDuplicate.java
 create mode 100644 collections/arraylist/arraylist-in-java/ArrayListExample.java
 create mode 100644 collections/arraylist/change-element-in-arraylist/ArrayListSetExample.java
 create mode 100644 collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample1.java
 create mode 100644 collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample2.java
 create mode 100644 collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample3.java
 create mode 100644 collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample4.java
 create mode 100644 collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample5.java
 create mode 100644 collections/arraylist/remove-element-from-arraylist/ArrayListRemoveExample.java
 create mode 100644 collections/arraylist/remove-element-from-arraylist/ArrayListRemoveExample2.java
 create mode 100644 collections/arraylist/remove-element-from-arraylist/ArrayListRemoveObjectExample.java
 create mode 100644 collections/arraylist/remove-element-from-arraylist/ArrayListRemoveObjectExample2.java
 create mode 100644 collections/arraylist/remove-element-from-arraylist/Employee.java

diff --git a/collections/arraylist/README.md b/collections/arraylist/README.md
new file mode 100644
index 0000000..ec09ddd
--- /dev/null
+++ b/collections/arraylist/README.md
@@ -0,0 +1,14 @@
+# Java Collections - ArrayList in Java
+
+This module contains articles related to ArrayList in Java.
+
+## Related articles
+
+- [ArrayList In Java](https://coderolls.com/arraylist-in-java/)
+- [How To Add An Element To ArrayList In Java?](https://coderolls.com/add-element-in-arraylist/)
+- [How To Change An Element In ArrayList?](https://coderolls.com/change-element-in-arraylist/)
+- [How To Remove An Element From An ArrayList?](https://coderolls.com/remove-element-from-arraylist/)
+- [Iterating the ArrayList In Java](https://coderolls.com/iterating-the-arraylist-in-java/)
+
+
+Visit [coderolls](https://coderolls.com/) to read more tutorials.
diff --git a/collections/arraylist/add-element-in-arraylist/ArrayListAddExample.java b/collections/arraylist/add-element-in-arraylist/ArrayListAddExample.java
new file mode 100644
index 0000000..35fe325
--- /dev/null
+++ b/collections/arraylist/add-element-in-arraylist/ArrayListAddExample.java
@@ -0,0 +1,33 @@
+package ArrayListAddExample;
+
+import java.util.ArrayList;
+
+/**
+ * A Java program to add an element at the specific index.
+ * 
+ * The add(int index, E element) method will add 
+ * an element at the specified index in ArrayList.
+ * 
+ * @author Guarav Kukade at coderolls.com
+ *
+ */
+public class ArrayListAddExample {
+
+	public static void main(String[] args) {
+		
+		ArrayList<String> arrayList = new ArrayList<String>();
+		
+		//adding elements to the arrayList using normal add method
+		arrayList.add("Gaurav");
+		arrayList.add("Shyam");
+		
+		System.out.println(arrayList);// [Gaurav, Shyam]
+		
+		// adding an element to  the arrayList at index 1
+		arrayList.add(1, "Saurav");
+		
+		System.out.println(arrayList); // [Gaurav, Saurav, Shyam]
+
+	}
+
+}
diff --git a/collections/arraylist/add-element-in-arraylist/ArrayListExample.java b/collections/arraylist/add-element-in-arraylist/ArrayListExample.java
new file mode 100644
index 0000000..4dbdbcf
--- /dev/null
+++ b/collections/arraylist/add-element-in-arraylist/ArrayListExample.java
@@ -0,0 +1,34 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+
+/**
+ * A Java program to add an element to the list.
+ * 
+ * The add(E e) method will add an element to 
+ * the end of the arrayList.
+ * 
+ * @author Guarav Kukade at coderolls.com
+ *
+ */
+public class ArrayListExample {
+
+	public static void main(String[] args) {
+		
+		ArrayList<String> arrayList = new ArrayList<String>();
+		
+		//adding elements to the arrayList
+		arrayList.add("Gaurav");
+		arrayList.add("Shyam");
+		
+		System.out.println(arrayList);// [Gaurav, Shyam]
+		
+		// adding an element to  the arrayList
+		// element will be added to the end of the arrayList
+		arrayList.add("Saurav");
+		
+		System.out.println(arrayList); // [Gaurav, Shyam, Saurav]
+
+	}
+
+}
diff --git a/collections/arraylist/arraylist-in-java/ArrayListDuplicate.java b/collections/arraylist/arraylist-in-java/ArrayListDuplicate.java
new file mode 100644
index 0000000..ac10779
--- /dev/null
+++ b/collections/arraylist/arraylist-in-java/ArrayListDuplicate.java
@@ -0,0 +1,20 @@
+package com.gaurav.ExProject;
+
+import java.util.ArrayList;
+
+public class ArrayListDuplicate {
+
+	public static void main(String[] args) {
+		ArrayList<String> arrayList = new ArrayList<String>();
+		
+		arrayList.add("Gaurav");
+		arrayList.add("Shyam");
+		arrayList.add("Saurav");
+		arrayList.add("Samiksha");
+		arrayList.add("Rina");
+		arrayList.add("Rina");
+		
+		System.out.println(arrayList);
+
+	}
+}
diff --git a/collections/arraylist/arraylist-in-java/ArrayListExample.java b/collections/arraylist/arraylist-in-java/ArrayListExample.java
new file mode 100644
index 0000000..8c4b065
--- /dev/null
+++ b/collections/arraylist/arraylist-in-java/ArrayListExample.java
@@ -0,0 +1,26 @@
+package com.gaurav.ExProject;
+
+import java.util.ArrayList;
+
+/**
+ * A Java program showing arraylist maintains the insertion order.
+ * 
+ * @author gaurav
+ *
+ */
+public class ArrayListExample {
+
+	public static void main(String[] args) {
+		
+		ArrayList<String> arrayList = new ArrayList<String>();
+		
+		arrayList.add("Gaurav");
+		arrayList.add("Shyam");
+		arrayList.add("Saurav");
+		arrayList.add("Samiksha");
+		arrayList.add("Rina");
+		
+		System.out.println(arrayList);
+	}
+
+}
diff --git a/collections/arraylist/change-element-in-arraylist/ArrayListSetExample.java b/collections/arraylist/change-element-in-arraylist/ArrayListSetExample.java
new file mode 100644
index 0000000..245ffc3
--- /dev/null
+++ b/collections/arraylist/change-element-in-arraylist/ArrayListSetExample.java
@@ -0,0 +1,34 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+
+/**
+ * A java program to change an element at 
+ * particular index in ArrayList.
+ * 
+ * We can use 'public E set(int index, E element)' method
+ * to change an element.
+ * 
+ * @author Guarav Kukade at coderolls.com
+ *
+ */
+public class ArrayListSetExample {
+
+	public static void main(String[] args) {
+ArrayList<String> arrayList = new ArrayList<String>();
+		
+		//adding elements to the arrayList using normal add method
+		arrayList.add("Gaurav");
+		arrayList.add("Shyam");
+		arrayList.add("Pradnya");
+		
+		System.out.println(arrayList);// [Gaurav, Shyam, Pradnya]
+		
+		// change an element at index 1
+		arrayList.set(1, "Saurav");
+		
+		System.out.println(arrayList); // [Gaurav, Saurav, Pradnya]
+
+	}
+
+}
diff --git a/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample1.java b/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample1.java
new file mode 100644
index 0000000..b18f159
--- /dev/null
+++ b/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample1.java
@@ -0,0 +1,33 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to iterate through arraylist 
+ * using the basic for loop.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListIterateExample1 {
+    
+    public static void main (String[] args) {
+        
+        List<String> list = new ArrayList<String>();
+        
+        list.add("Monday");
+        list.add("Tuesday");
+        list.add("Wednesday");
+        list.add("Thursday");
+        list.add("Friday");
+        list.add("Saturday");
+        list.add("Sunday");
+        
+        System.out.println("Iterating through ArrayList using the basic for loop.......\n");
+        
+        for(int i =0; i <list.size(); i++){
+            System.out.println("Object form the ArrayList at "+ i + " is " + list.get(i));
+        }
+    }
+}
\ No newline at end of file
diff --git a/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample2.java b/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample2.java
new file mode 100644
index 0000000..6c33650
--- /dev/null
+++ b/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample2.java
@@ -0,0 +1,34 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to iterate through arraylist 
+ * using enhanced for loop i.e. For-each loop.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListIterateExample2 {
+    
+    public static void main (String[] args) {
+        
+        List<String> list = new ArrayList<String>();
+        
+        list.add("Monday");
+        list.add("Tuesday");
+        list.add("Wednesday");
+        list.add("Thursday");
+        list.add("Friday");
+        list.add("Saturday");
+        list.add("Sunday");
+        
+        System.out.println("Iterating through ArrayList using enhanced for loop i.e. For-each loop.......\n");
+        
+        for(String str:list){
+        	//we get 'str' in for-each loop
+            System.out.println("Object form the ArrayList is " + str);
+        }
+    }
+}
\ No newline at end of file
diff --git a/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample3.java b/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample3.java
new file mode 100644
index 0000000..9726af2
--- /dev/null
+++ b/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample3.java
@@ -0,0 +1,36 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to iterate through arraylist 
+ * using while loop.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListIterateExample3 {
+    
+    public static void main (String[] args) {
+        
+        List<String> list = new ArrayList<String>();
+        
+        list.add("Monday");
+        list.add("Tuesday");
+        list.add("Wednesday");
+        list.add("Thursday");
+        list.add("Friday");
+        list.add("Saturday");
+        list.add("Sunday");
+        
+        System.out.println("Iterating through ArrayList using while loop.......\n");
+        
+        int i=0;
+        // while loop condition will be true till i is less the the list size
+        while (list.size()>i) {
+        	System.out.println("Object form the ArrayList at "+ i + " is " + list.get(i));
+        	i++;
+		}
+    }
+}
\ No newline at end of file
diff --git a/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample4.java b/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample4.java
new file mode 100644
index 0000000..629f3ea
--- /dev/null
+++ b/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample4.java
@@ -0,0 +1,41 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+/**
+ * A java program to iterate through arraylist 
+ * using Iterator interface.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListIterateExample4 {
+    
+    public static void main (String[] args) {
+        
+        List<String> list = new ArrayList<String>();
+        
+        list.add("Monday");
+        list.add("Tuesday");
+        list.add("Wednesday");
+        list.add("Thursday");
+        list.add("Friday");
+        list.add("Saturday");
+        list.add("Sunday");
+        
+        System.out.println("Iterating through ArrayList using Iterator interface........\n");
+        
+        // getting iterator
+        Iterator iterator = list.iterator();
+        
+        // hasNext() returns true only if object is available at next call
+        while (iterator.hasNext()) {
+        	
+        	//next() returns obejct, we can cast it to reuqired type
+        	String str = (String) iterator.next();
+        	System.out.println("Object form the ArrayList is " + str);
+		}
+    }
+}
\ No newline at end of file
diff --git a/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample5.java b/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample5.java
new file mode 100644
index 0000000..fc7b89d
--- /dev/null
+++ b/collections/arraylist/iterating-the-arraylist-in-java/ArrayListIterateExample5.java
@@ -0,0 +1,32 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to iterate through arraylist 
+ * using forEach method and lamda expression.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListIterateExample5 {
+    
+    public static void main (String[] args) {
+        
+        List<String> list = new ArrayList<String>();
+        
+        list.add("Monday");
+        list.add("Tuesday");
+        list.add("Wednesday");
+        list.add("Thursday");
+        list.add("Friday");
+        list.add("Saturday");
+        list.add("Sunday");
+        
+        System.out.println("Iterating through ArrayList using forEach method and lamda expression........\n");
+        
+        // add lambda expressionin the foreach loop
+        list.forEach(s -> System.out.println("Object form the ArrayList is "+ s));
+    }
+}
\ No newline at end of file
diff --git a/collections/arraylist/remove-element-from-arraylist/ArrayListRemoveExample.java b/collections/arraylist/remove-element-from-arraylist/ArrayListRemoveExample.java
new file mode 100644
index 0000000..65c87a3
--- /dev/null
+++ b/collections/arraylist/remove-element-from-arraylist/ArrayListRemoveExample.java
@@ -0,0 +1,30 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+
+/**
+ * A Java program to remove an element from ArrayList
+ * using the remove(Object o) method.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListRemoveExample {
+
+	public static void main(String[] args) {
+		
+		ArrayList<String> arrayList = new ArrayList<String>();
+		
+		//adding elements to the arrayList using normal add method
+		arrayList.add("Red");
+		arrayList.add("Green");
+		arrayList.add("Pink");
+		
+		System.out.println("ArrayList before removing an element"+ arrayList); // ArrayList before removing an element[Red, Green, Pink]
+		
+		//Remove "Pink" from the arrayList
+		arrayList.remove("Pink");
+		
+		System.out.println("ArrayList after removing an element"+ arrayList);// ArrayList after removing an element[Red, Green]
+	}
+}
diff --git a/collections/arraylist/remove-element-from-arraylist/ArrayListRemoveExample2.java b/collections/arraylist/remove-element-from-arraylist/ArrayListRemoveExample2.java
new file mode 100644
index 0000000..b9f098a
--- /dev/null
+++ b/collections/arraylist/remove-element-from-arraylist/ArrayListRemoveExample2.java
@@ -0,0 +1,32 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+
+/**
+ * A Java program to remove an element from ArrayList
+ * using the remove(int index) method.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListRemoveExample2 {
+
+	public static void main(String[] args) {
+		
+		ArrayList<String> arrayList = new ArrayList<String>();
+		
+		//adding elements to the arrayList using normal add method
+		arrayList.add("Apple");
+		arrayList.add("Orange");
+		arrayList.add("Guava");
+		arrayList.add("Banana");
+		
+		System.out.println("ArrayList before removing an element"+ arrayList); // ArrayList before removing an element[Apple, Orange, Guava, Banana]
+		
+		//Remove the element at the specified index i.e. 2
+		//Remove "Guava" from the arrayList
+		arrayList.remove(2);
+		
+		System.out.println("ArrayList after removing an element"+ arrayList);// ArrayList after removing an element[Apple, Orange, Banana]
+	}
+}
diff --git a/collections/arraylist/remove-element-from-arraylist/ArrayListRemoveObjectExample.java b/collections/arraylist/remove-element-from-arraylist/ArrayListRemoveObjectExample.java
new file mode 100644
index 0000000..1519655
--- /dev/null
+++ b/collections/arraylist/remove-element-from-arraylist/ArrayListRemoveObjectExample.java
@@ -0,0 +1,35 @@
+package com.gaurav.ExProject2;
+
+import java.util.ArrayList;
+/**
+ * A Java program to remove an object from ArrayList
+ * using the remove(int index) method.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListRemoveObjectExample {
+
+	public static void main(String[] args) {
+		
+		ArrayList<Employee> arrayList = new ArrayList<Employee>();
+		
+		//create Employee objects
+		Employee john = new Employee(100, "John Doe", 20000);
+		Employee nathasha = new Employee(101, "Natasha Putin", 28000);
+		Employee remo = new Employee(102, "Remo Smith", 40000);
+		
+		//adding employee objects to the arrayList using normal add method
+		arrayList.add(john);
+		arrayList.add(nathasha);
+		arrayList.add(remo);
+		
+		System.out.println("ArrayList before removing an employee Object:\n"+ arrayList); 
+		
+		//Remove object using the remo0ve(Object o) method 
+		//Remove employee nathasha from the arrayList
+		arrayList.remove(nathasha);
+		
+		System.out.println("\nArrayList after removing an employee Object:\n"+ arrayList);
+	}
+}
diff --git a/collections/arraylist/remove-element-from-arraylist/ArrayListRemoveObjectExample2.java b/collections/arraylist/remove-element-from-arraylist/ArrayListRemoveObjectExample2.java
new file mode 100644
index 0000000..7117524
--- /dev/null
+++ b/collections/arraylist/remove-element-from-arraylist/ArrayListRemoveObjectExample2.java
@@ -0,0 +1,36 @@
+package com.gaurav.ExProject2;
+
+import java.util.ArrayList;
+
+/**
+ * A Java program to remove an object from ArrayList
+ * using the remove(int index) method.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListRemoveObjectExample2 {
+
+	public static void main(String[] args) {
+		
+		ArrayList<Employee> arrayList = new ArrayList<Employee>();
+		
+		//create Employee objects
+		Employee john = new Employee(100, "John Doe", 20000);
+		Employee nathasha = new Employee(101, "Natasha Putin", 28000);
+		Employee remo = new Employee(102, "Remo Smith", 40000);
+		
+		//adding employee objects to the arrayList using normal add method
+		arrayList.add(john);
+		arrayList.add(nathasha);
+		arrayList.add(remo);
+		
+		System.out.println("ArrayList before removing an employee Object:\n"+ arrayList); 
+		
+		//Remove object using the remove(int index) method 
+		//Remove employee nathasha from the arrayList, so pass natasha's index
+		arrayList.remove(1);
+		
+		System.out.println("\nArrayList after removing an employee Object:\n"+ arrayList);
+	}
+}
diff --git a/collections/arraylist/remove-element-from-arraylist/Employee.java b/collections/arraylist/remove-element-from-arraylist/Employee.java
new file mode 100644
index 0000000..0e63c8f
--- /dev/null
+++ b/collections/arraylist/remove-element-from-arraylist/Employee.java
@@ -0,0 +1,52 @@
+package com.gaurav.ExProject2;
+/**
+ * An employee class for ArrayList remove example
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class Employee {
+	
+	private int id;
+	
+	private String name;
+	
+	private int salary;
+	
+	// a constructor will all the fields
+	public Employee(int id, String name, int salary) {
+		this.id = id;
+		this.name = name;
+		this.salary = salary;
+	}
+	
+	// getters and setters for the variables
+	public int getId() {
+		return id;
+	}
+
+	public void setId(int id) {
+		this.id = id;
+	}
+
+	public String getName() {
+		return name;
+	}
+
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	public int getSalary() {
+		return salary;
+	}
+
+	public void setSalary(int salary) {
+		this.salary = salary;
+	}
+	
+	// Override to string method to print student objects
+	@Override
+	public String toString() {
+		return "{"+this.getId()+", "+ this.getName()+ ", "+this.getSalary()+"}";
+	}
+}

From 80b7dcddbfee3006f1fa96e9d7856e704f6e0fc3 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Sun, 5 Dec 2021 11:39:35 +0530
Subject: [PATCH 06/31] Add java programs to convert an arraylist to array

---
 .../ArrayListToArray.java                     | 39 +++++++++++++++++++
 .../ArrayListToArray2.java                    | 39 +++++++++++++++++++
 2 files changed, 78 insertions(+)
 create mode 100644 collections/arraylist/convert-arraylist-to-array/ArrayListToArray.java
 create mode 100644 collections/arraylist/convert-arraylist-to-array/ArrayListToArray2.java

diff --git a/collections/arraylist/convert-arraylist-to-array/ArrayListToArray.java b/collections/arraylist/convert-arraylist-to-array/ArrayListToArray.java
new file mode 100644
index 0000000..1e0fd8b
--- /dev/null
+++ b/collections/arraylist/convert-arraylist-to-array/ArrayListToArray.java
@@ -0,0 +1,39 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+
+/**
+ * A java program to convert an ArrayList to array using
+ * toArray method.
+ * 
+ * toArray() method returns Object[]
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListToArray {
+
+	public static void main(String[] args) {
+		ArrayList<String> arrayList = new ArrayList<String>();
+		
+		//adding elements to the arrayList
+		arrayList.add("Meta");
+		arrayList.add("Apple");
+		arrayList.add("Amazon");
+		arrayList.add("Netflix");
+		arrayList.add("Microsoft");
+		arrayList.add("Google");
+		
+		System.out.println("ArrayList: \n"+ arrayList);
+		
+		// convert ArrayList to array
+		Object[] objects = arrayList.toArray();
+		
+		System.out.println("\nArray:");
+		
+		//we will receive the object array, so iterate on it to print each element
+		for(Object obj:objects) {
+			System.out.println(obj);
+		}
+	}
+}
diff --git a/collections/arraylist/convert-arraylist-to-array/ArrayListToArray2.java b/collections/arraylist/convert-arraylist-to-array/ArrayListToArray2.java
new file mode 100644
index 0000000..345ef39
--- /dev/null
+++ b/collections/arraylist/convert-arraylist-to-array/ArrayListToArray2.java
@@ -0,0 +1,39 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+
+/**
+ * A java program to convert an ArrayList to array using
+ * toArray method.
+ * 
+ * toArray(T[] a) method returns T[]
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListToArray2 {
+
+	public static void main(String[] args) {
+		ArrayList<String> arrayList = new ArrayList<String>();
+		
+		//adding elements to the arrayList
+		arrayList.add("Meta");
+		arrayList.add("Apple");
+		arrayList.add("Amazon");
+		arrayList.add("Netflix");
+		arrayList.add("Microsoft");
+		arrayList.add("Google");
+		
+		System.out.println("ArrayList: \n"+ arrayList);
+		
+		// convert ArrayList to array
+		// pass a new String array of the arrayList size as a param to toArray
+		String[] elements = arrayList.toArray(new String[arrayList.size()]);
+		
+		System.out.println("\nArray:");
+		//we will receive the string array, so iterate on it to print each element
+		for(String str:elements) {
+			System.out.println(str);
+		}
+	}
+}

From 50e629ee1d3bdee15e127bcfb8698a8578c83679 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Sun, 5 Dec 2021 13:31:54 +0530
Subject: [PATCH 07/31] update java program to convert arraylist to array

---
 .../convert-arraylist-to-array/ArrayListToArray2.java        | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/collections/arraylist/convert-arraylist-to-array/ArrayListToArray2.java b/collections/arraylist/convert-arraylist-to-array/ArrayListToArray2.java
index 345ef39..88b17da 100644
--- a/collections/arraylist/convert-arraylist-to-array/ArrayListToArray2.java
+++ b/collections/arraylist/convert-arraylist-to-array/ArrayListToArray2.java
@@ -28,7 +28,10 @@ public static void main(String[] args) {
 		
 		// convert ArrayList to array
 		// pass a new String array of the arrayList size as a param to toArray
-		String[] elements = arrayList.toArray(new String[arrayList.size()]);
+		//String[] elements = arrayList.toArray(new String[arrayList.size()]);
+		
+		//kindly read the 'Important Note' below
+		String[] elements = arrayList.toArray(new String[0]);
 		
 		System.out.println("\nArray:");
 		//we will receive the string array, so iterate on it to print each element

From c1c9ebcdfe9f5cff041801ec2f37cf5986dde9df Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Tue, 7 Dec 2021 12:22:31 +0530
Subject: [PATCH 08/31] Add for-each loop and arraylist get method example

---
 .../ArrayListGetExample.java                  | 41 +++++++++++++++++++
 .../for-each-loop/ArrayForEachExample.java    | 23 +++++++++++
 .../ArrayListForEachExample.java              | 36 ++++++++++++++++
 3 files changed, 100 insertions(+)
 create mode 100644 collections/arraylist/arraylist-get-method/ArrayListGetExample.java
 create mode 100644 java-basic/for-each-loop/ArrayForEachExample.java
 create mode 100644 java-basic/for-each-loop/ArrayListForEachExample.java

diff --git a/collections/arraylist/arraylist-get-method/ArrayListGetExample.java b/collections/arraylist/arraylist-get-method/ArrayListGetExample.java
new file mode 100644
index 0000000..b75cd5b
--- /dev/null
+++ b/collections/arraylist/arraylist-get-method/ArrayListGetExample.java
@@ -0,0 +1,41 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to get the element by 
+ * its index using the get() method
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListGetExample {
+
+	public static void main(String[] args) {
+		
+        List<String> list = new ArrayList<String>();
+        
+        list.add("Monday");
+        list.add("Tuesday");
+        list.add("Wednesday");
+        list.add("Thursday");
+        list.add("Friday");
+        list.add("Saturday");
+        list.add("Sunday");
+        
+        System.out.println("Arraylist:"+ list);
+        
+        // get element at index 3
+        String element = list.get(3);
+        System.out.println("\nElement at index 3 is "+ element);
+        
+        System.out.println("\nUsing get() method in for loop: \n");
+        
+        // using the get(0 method in for loop
+        for(int i=0; i<list.size(); i++) {
+        	System.out.println("The element at index "+i+" is "+ list.get(i));
+        }
+	}
+
+}
diff --git a/java-basic/for-each-loop/ArrayForEachExample.java b/java-basic/for-each-loop/ArrayForEachExample.java
new file mode 100644
index 0000000..8ab7142
--- /dev/null
+++ b/java-basic/for-each-loop/ArrayForEachExample.java
@@ -0,0 +1,23 @@
+package com.gaurav.ExProject.ArrayList;
+
+/**
+ * A java program to traverse the array using the 
+ * for-each loop i.e. enhanced for loop
+ * 
+ * @author Guarav Kukade at coderolls.com
+ *
+ */
+public class ArrayForEachExample {
+
+	public static void main(String[] args) {
+		
+		// create an array of marks
+		int[] numbers = { 88, 95, 65, 76, 78, 45, 95, 96, 56};
+		
+		// traversing the array using for-each loop
+		for(int number: numbers) {
+			
+			System.out.println("The number is "+ number);
+		}
+	}
+}
diff --git a/java-basic/for-each-loop/ArrayListForEachExample.java b/java-basic/for-each-loop/ArrayListForEachExample.java
new file mode 100644
index 0000000..01daa0d
--- /dev/null
+++ b/java-basic/for-each-loop/ArrayListForEachExample.java
@@ -0,0 +1,36 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to traverse the collection using
+ * the for-each loop i.e. enhanced for loop
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListForEachExample {
+
+	public static void main(String[] args) {
+		
+		// create an empty arraylist of Integer
+		List<Integer> numbers = new ArrayList<Integer>();
+		
+		//add number to the list
+		numbers.add(1);
+		numbers.add(8);
+		numbers.add(8);
+		numbers.add(5);
+		numbers.add(4);
+		numbers.add(6);
+		numbers.add(3);
+		numbers.add(2);
+		numbers.add(9);
+		
+		//traversing the collection using for-each loop
+		for(Integer number: numbers) {
+			System.out.println("The number is "+ number);
+		}
+	}
+}

From a75cdfa90b0e0f86d64097fc8f60fe0da7bce42c Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Tue, 14 Dec 2021 19:39:31 +0530
Subject: [PATCH 09/31] Add blopost java programs

---
 .../ArrayListClearMethodExample.java          | 38 +++++++++++++++++++
 .../ArrayListContainsMethodExample.java       | 34 +++++++++++++++++
 .../MyArrayList.java                          | 37 ++++++++++++++++++
 .../ReverseStringUsingRecursion.java          | 23 +++++++++++
 4 files changed, 132 insertions(+)
 create mode 100644 collections/arraylist/arraylist-clear-method-in-java/ArrayListClearMethodExample.java
 create mode 100644 collections/arraylist/arraylist-contains-method/ArrayListContainsMethodExample.java
 create mode 100644 collections/arraylist/arraylist-removerange-method/MyArrayList.java
 create mode 100644 java-string/java-reverse-string-using-recursion/ReverseStringUsingRecursion.java

diff --git a/collections/arraylist/arraylist-clear-method-in-java/ArrayListClearMethodExample.java b/collections/arraylist/arraylist-clear-method-in-java/ArrayListClearMethodExample.java
new file mode 100644
index 0000000..46b70b0
--- /dev/null
+++ b/collections/arraylist/arraylist-clear-method-in-java/ArrayListClearMethodExample.java
@@ -0,0 +1,38 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to remove all the elements 
+ * of ArrayList using the clear() method.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListClearMethodExample {
+
+	public static void main(String[] args) {
+		
+		// create an arraylist cities
+		List<String> cities = new ArrayList<String>();
+		
+		// add string objects in 'cities'
+		cities.add("New York City");
+		cities.add("Los Angeles");
+		cities.add("Mountain View");
+		cities.add("Austin");
+		cities.add("Atlanta");
+		
+		// printing the cities
+		System.out.println("Before invoking the clear() method");
+		System.out.println("Cities: "+ cities); //print the arraylist with elements
+		System.out.println("cities size: "+ cities.size());
+		
+		//invoke the clear() method on arraylist
+		cities.clear();
+		System.out.println("\nAfter invoking the clear() method");
+		System.out.println("Cities: "+ cities); // empty arraylist
+		System.out.println("cities size: "+ cities.size());
+	}
+}
diff --git a/collections/arraylist/arraylist-contains-method/ArrayListContainsMethodExample.java b/collections/arraylist/arraylist-contains-method/ArrayListContainsMethodExample.java
new file mode 100644
index 0000000..a89aecf
--- /dev/null
+++ b/collections/arraylist/arraylist-contains-method/ArrayListContainsMethodExample.java
@@ -0,0 +1,34 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+/**
+ * A java program to check if the ArrayList 
+ * contains the specified element.
+ * 
+ * @author Gaurav Kukade a coderolls.com
+ *
+ */
+public class ArrayListContainsMethodExample {
+
+	public static void main(String[] args) {
+		
+		//create an empty arraylist object 'states'
+		List<String> states = new ArrayList<String>();
+		
+		//add state in the arraylist 
+		states.add("California");
+		states.add("Texas");
+		states.add("Florida");
+		states.add("New Jersey");
+		states.add("Washington");
+		
+		//check if states contains florida
+		boolean isPresent1 = states.contains("Florida");
+		System.out.println("Is Florida present in the list: "+ isPresent1);
+		
+		//check if states contains alaska
+		boolean isPresent2 =states.contains("Alaska");
+		System.out.println("\nIs Alaska present in the list: "+ isPresent2);
+	}
+}
diff --git a/collections/arraylist/arraylist-removerange-method/MyArrayList.java b/collections/arraylist/arraylist-removerange-method/MyArrayList.java
new file mode 100644
index 0000000..a6bcc81
--- /dev/null
+++ b/collections/arraylist/arraylist-removerange-method/MyArrayList.java
@@ -0,0 +1,37 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to remove the range of elements from 
+ * the MyArraylist (a class which extends the ArrayList)
+ * using the removeRange() method.
+ * 
+ * The removeRange() method is protected and is accessed in class,
+ * subclasses and in a package, but not public.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class MyArrayList extends ArrayList<String> {
+
+	public static void main(String[] args) {
+		
+		MyArrayList myArrayList = new MyArrayList();
+        
+		myArrayList.add("Monday");
+		myArrayList.add("Tuesday");
+		myArrayList.add("Wednesday");
+		myArrayList.add("Thursday");
+		myArrayList.add("Friday");
+		myArrayList.add("Saturday");
+		myArrayList.add("Sunday");
+        
+        System.out.println("Arraylist before removing range of elments:\n"+ myArrayList);
+  
+        myArrayList.removeRange(2, 4);
+        
+        System.out.println("\nArraylist after removing range of elments:\n"+ myArrayList); 
+	}
+}
diff --git a/java-string/java-reverse-string-using-recursion/ReverseStringUsingRecursion.java b/java-string/java-reverse-string-using-recursion/ReverseStringUsingRecursion.java
new file mode 100644
index 0000000..77a8f21
--- /dev/null
+++ b/java-string/java-reverse-string-using-recursion/ReverseStringUsingRecursion.java
@@ -0,0 +1,23 @@
+package ArrayListAddExample;
+/**
+ * A java program to reverse a striong using recursion.
+ * 
+ * @author gaurav
+ *
+ */
+public class ReverseStringUsingRecursion {
+
+	public static void main(String[] args) {
+		
+		String str = "Hello";
+		System.out.println(reverse(str));
+
+	}
+
+	public static String reverse(String str) {
+	    if ((null == str) || (str.length() <= 1)) {
+	        return str;
+	    }
+	    return reverse(str.substring(1)) + str.charAt(0);
+	}
+}

From 3f27168a6371ca90a9f77402a39971b840719022 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Fri, 17 Dec 2021 20:03:04 +0530
Subject: [PATCH 10/31] Add blogpost example for the arraylist in java

---
 .../ArrayListAddAllExample.java               | 41 +++++++++++++++
 .../ArrayListAddAllExample2.java              | 43 ++++++++++++++++
 .../ArrayListIndexOfExample.java              | 38 ++++++++++++++
 .../ArrayListLastIndexOfExample.java          | 39 ++++++++++++++
 .../ArrayListRetainAllExample.java            | 51 +++++++++++++++++++
 .../RetainAllNullPointerExceptionExample.java | 39 ++++++++++++++
 .../ArrayListSubListExample.java              | 33 ++++++++++++
 .../SubListMethodExceptionExample1.java       | 32 ++++++++++++
 .../SubListMethodExceptionExample2.java       | 32 ++++++++++++
 9 files changed, 348 insertions(+)
 create mode 100644 collections/arraylist/arraylist-addall-method-in-java/ArrayListAddAllExample.java
 create mode 100644 collections/arraylist/arraylist-addall-method-in-java/ArrayListAddAllExample2.java
 create mode 100644 collections/arraylist/arraylist-indexOf-method/ArrayListIndexOfExample.java
 create mode 100644 collections/arraylist/arraylist-lastindexof-method/ArrayListLastIndexOfExample.java
 create mode 100644 collections/arraylist/arraylist-retainall-method/ArrayListRetainAllExample.java
 create mode 100644 collections/arraylist/arraylist-retainall-method/RetainAllNullPointerExceptionExample.java
 create mode 100644 collections/arraylist/sublist-method-in-arraylist/ArrayListSubListExample.java
 create mode 100644 collections/arraylist/sublist-method-in-arraylist/SubListMethodExceptionExample1.java
 create mode 100644 collections/arraylist/sublist-method-in-arraylist/SubListMethodExceptionExample2.java

diff --git a/collections/arraylist/arraylist-addall-method-in-java/ArrayListAddAllExample.java b/collections/arraylist/arraylist-addall-method-in-java/ArrayListAddAllExample.java
new file mode 100644
index 0000000..731829d
--- /dev/null
+++ b/collections/arraylist/arraylist-addall-method-in-java/ArrayListAddAllExample.java
@@ -0,0 +1,41 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A Java program to add all elements of the specified collection
+ * to the end of the ArrayList
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListAddAllExample {
+
+	public static void main(String[] args) {
+		
+		// ArrayList contains actresses
+		List<String> actresses1 = new ArrayList<String>();
+		
+		actresses1.add("Natalie Portman");
+		actresses1.add("Abigail Anderson");
+		actresses1.add("Jennifer Lawrence");
+		
+		System.out.println("Actresses collection 1: \n"+ actresses1 );
+		
+		// ArrayList contains actresses
+		List<String> actresses2 = new ArrayList<String>();
+		
+		
+		
+		actresses2.add("Angelina Jolie");
+		actresses2.add("Scarlett Johansson");
+		
+		System.out.println("Actresses collection 2: \n"+ actresses2);
+		
+		// Add actresses2 collections all elements to actresses1 collection using addAll()method
+		actresses1.addAll(actresses2);
+		
+		System.out.println("Actresses : \n"+ actresses1);
+	}
+}
diff --git a/collections/arraylist/arraylist-addall-method-in-java/ArrayListAddAllExample2.java b/collections/arraylist/arraylist-addall-method-in-java/ArrayListAddAllExample2.java
new file mode 100644
index 0000000..d32e64e
--- /dev/null
+++ b/collections/arraylist/arraylist-addall-method-in-java/ArrayListAddAllExample2.java
@@ -0,0 +1,43 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A Java program to add all elements of the specified collection
+ * to the ArrayList from a particular index 
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListAddAllExample2 {
+
+	public static void main(String[] args) {
+		
+		// ArrayList containing entrepreneurs
+		List<String> entrepreneurs1 = new ArrayList<String>();
+		
+		entrepreneurs1.add("Bill Gates");
+		entrepreneurs1.add("Steve Jobs");
+		entrepreneurs1.add("Jeff Bezos");
+		entrepreneurs1.add("Richard Branson");
+		entrepreneurs1.add("Mark Cuban");
+		
+		System.out.println("Entrepreneurs collection 1: \n"+ entrepreneurs1 );
+		
+		// ArrayList containing entrepreneurs
+		List<String> entrepreneurs2 = new ArrayList<String>();
+		
+		entrepreneurs2.add("Mark Zuckerberg");
+		entrepreneurs2.add("Larry Page");
+		entrepreneurs2.add("Larry Ellison");
+		
+		System.out.println("Entrepreneurs collection 2: \n"+ entrepreneurs2);
+		
+		// Add entrepreneurs2 collections all elements to entrepreneurs1 collection
+		// starting from index 2
+		entrepreneurs1.addAll(2, entrepreneurs2);
+		
+		System.out.println("Entrepreneurs : \n"+ entrepreneurs1);
+	}
+}
diff --git a/collections/arraylist/arraylist-indexOf-method/ArrayListIndexOfExample.java b/collections/arraylist/arraylist-indexOf-method/ArrayListIndexOfExample.java
new file mode 100644
index 0000000..43b8260
--- /dev/null
+++ b/collections/arraylist/arraylist-indexOf-method/ArrayListIndexOfExample.java
@@ -0,0 +1,38 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to explain the indexOf() method
+ * of the arrayList class in java.
+ * 
+ * @author Gaurav Kukade
+ */
+public class ArrayListIndexOfExample {
+
+	public static void main(String[] args) {
+		
+		// create an empty arraylist object 'states'
+		List<String> states = new ArrayList<String>();
+
+		// add state in the arraylist, Florida multiple times
+		states.add("California");
+		states.add("Texas");
+		states.add("Florida");
+		states.add("Florida");
+		states.add("New Jersey");
+		states.add("Washington");
+		states.add("Florida");
+		
+		int index = states.indexOf("Florida");
+		
+		//prints index of the first occurrences of Florida i.e. 2
+		System.out.println("The index of the Florida: "+ index);
+		
+		//trying get the index of element, which is not present
+		int index2 = states.indexOf("Alaska");
+		
+		System.out.println("The index of the Alaska: " + index2);
+	}
+}
diff --git a/collections/arraylist/arraylist-lastindexof-method/ArrayListLastIndexOfExample.java b/collections/arraylist/arraylist-lastindexof-method/ArrayListLastIndexOfExample.java
new file mode 100644
index 0000000..52ff0ab
--- /dev/null
+++ b/collections/arraylist/arraylist-lastindexof-method/ArrayListLastIndexOfExample.java
@@ -0,0 +1,39 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to explain the indexOf() method
+ * of the arrayList class in java.
+ * 
+ * @author Gaurav Kukade
+ */
+public class ArrayListLastIndexOfExample {
+	
+public static void main(String[] args) {
+		
+		// create an empty arraylist object 'states'
+		List<String> states = new ArrayList<String>();
+
+		// add state in the arraylist, Florida multiple times
+		states.add("California");
+		states.add("Texas");
+		states.add("Florida");
+		states.add("Florida");
+		states.add("New Jersey");
+		states.add("Washington");
+		states.add("Florida");
+		
+		int index = states.lastIndexOf("Florida");
+		
+		//prints index of the last occurrences of Florida i.e. 6
+		System.out.println("The last index of the Florida: "+ index);
+		
+		//trying get the index of element, which is not present
+		int index2 = states.lastIndexOf("Alaska");
+		
+		System.out.println("The index of the Alaska: " + index2);
+	}
+
+}
\ No newline at end of file
diff --git a/collections/arraylist/arraylist-retainall-method/ArrayListRetainAllExample.java b/collections/arraylist/arraylist-retainall-method/ArrayListRetainAllExample.java
new file mode 100644
index 0000000..265abbe
--- /dev/null
+++ b/collections/arraylist/arraylist-retainall-method/ArrayListRetainAllExample.java
@@ -0,0 +1,51 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to to eplain the retainAll() method of the Arraylist class.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListRetainAllExample {
+
+	public static void main(String[] args) {
+
+		//create an empty arraylist of Integer to retain elements
+		List<Integer> numbers1 = new ArrayList<Integer>();
+
+		//add number to the list
+		numbers1.add(4);
+		numbers1.add(5);
+		numbers1.add(6);
+		
+		
+		//create an empty arraylist of Integer
+		List<Integer> numbers2 = new ArrayList<Integer>();
+
+		// add number to the list
+		numbers2.add(1);
+		numbers2.add(2);
+		numbers2.add(3);
+		numbers2.add(4);
+		numbers2.add(5);
+		numbers2.add(6);
+		numbers2.add(7);
+		numbers2.add(8);
+		numbers2.add(9);
+		
+
+		System.out.println("Lists before the method call");
+		System.out.println("numbers1: "+ numbers1);
+		System.out.println("numbers2: "+ numbers2);
+		
+		//retain all the elements of numbers1 in the list numbers2
+		numbers2.retainAll(numbers1);
+		
+		System.out.println("\nLists after the method call");
+		System.out.println("numbers1: "+ numbers1);
+		System.out.println("numbers2: "+ numbers2);	
+	}
+}
diff --git a/collections/arraylist/arraylist-retainall-method/RetainAllNullPointerExceptionExample.java b/collections/arraylist/arraylist-retainall-method/RetainAllNullPointerExceptionExample.java
new file mode 100644
index 0000000..942c2ed
--- /dev/null
+++ b/collections/arraylist/arraylist-retainall-method/RetainAllNullPointerExceptionExample.java
@@ -0,0 +1,39 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+/**
+ * A java program to show the NullPointerException in retainAll() method
+ * of the arrayList class.
+ *  
+ * @author gaurav
+ *
+ */
+public class RetainAllNullPointerExceptionExample {
+
+	public static void main(String[] args) {
+		
+		//create an empty arraylist of Integer to retain elements
+		List<String> numbers1 = null;
+
+		//create an empty arraylist of Integer
+		List<Integer> numbers2 = new ArrayList<Integer>();
+
+		// add number to the list
+		numbers2.add(1);
+		numbers2.add(2);
+		numbers2.add(3);
+		numbers2.add(4);
+
+		System.out.println("Lists before the method call");
+		System.out.println("numbers1: "+ numbers1);
+		System.out.println("numbers2: "+ numbers2);
+		
+		//retain all the elements of numbers1 in the list numbers2
+		numbers2.retainAll(numbers1);
+		
+		System.out.println("\nLists after the method call");
+		System.out.println("numbers1: "+ numbers1);
+		System.out.println("numbers2: "+ numbers2);	
+	}
+}
diff --git a/collections/arraylist/sublist-method-in-arraylist/ArrayListSubListExample.java b/collections/arraylist/sublist-method-in-arraylist/ArrayListSubListExample.java
new file mode 100644
index 0000000..8a222ed
--- /dev/null
+++ b/collections/arraylist/sublist-method-in-arraylist/ArrayListSubListExample.java
@@ -0,0 +1,33 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to explain the subList() method of the ArrayList class in Java
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ *
+ */
+public class ArrayListSubListExample {
+
+	public static void main(String[] args) {
+
+		// create an empty arraylist object 'states'
+		List<String> states = new ArrayList<String>();
+
+		// add state in the arraylist
+		states.add("California");
+		states.add("Texas");
+		states.add("Florida");
+		states.add("New Jersey");
+		states.add("Washington");
+		
+		System.out.println("The states list: \n"+ states);
+		
+		// sublist the states list from 1 to 3 index
+		List<String> statesSubList = states.subList(1, 3);
+		
+		System.out.println("\nThe states sublist from index 1 (inclusive) to 3 (exclusive): \n"+ statesSubList);
+	}
+}
diff --git a/collections/arraylist/sublist-method-in-arraylist/SubListMethodExceptionExample1.java b/collections/arraylist/sublist-method-in-arraylist/SubListMethodExceptionExample1.java
new file mode 100644
index 0000000..7b9bbe3
--- /dev/null
+++ b/collections/arraylist/sublist-method-in-arraylist/SubListMethodExceptionExample1.java
@@ -0,0 +1,32 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to explain the subList() methods 
+ * IndexOutOfBoundsException exception case.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ */
+public class SubListMethodExceptionExample1 {
+
+	public static void main(String[] args) {
+		// create an empty arraylist object 'states'
+		List<String> states = new ArrayList<String>();
+
+		// add state in the arraylist
+		states.add("California");
+		states.add("Texas");
+		states.add("Florida");
+		states.add("New Jersey");
+		states.add("Washington");
+		
+		System.out.println("The states list: \n"+ states);
+		
+		// will throw IndexOutOfBoundsException
+		List<String> statesSubList = states.subList(1, 7); 
+		
+		System.out.println("\nThe states sublist from index 1 (inclusive) to 3 (exclusive): \n"+ statesSubList);
+	}
+}
diff --git a/collections/arraylist/sublist-method-in-arraylist/SubListMethodExceptionExample2.java b/collections/arraylist/sublist-method-in-arraylist/SubListMethodExceptionExample2.java
new file mode 100644
index 0000000..b134bc6
--- /dev/null
+++ b/collections/arraylist/sublist-method-in-arraylist/SubListMethodExceptionExample2.java
@@ -0,0 +1,32 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A java program to explain the subList() methods 
+ * IllegalArgumentException exception case.
+ * 
+ * @author Gaurav Kukade at coderolls.com
+ */
+public class SubListMethodExceptionExample2 {
+
+	public static void main(String[] args) {
+		// create an empty arraylist object 'states'
+		List<String> states = new ArrayList<String>();
+
+		// add state in the arraylist
+		states.add("California");
+		states.add("Texas");
+		states.add("Florida");
+		states.add("New Jersey");
+		states.add("Washington");
+		
+		System.out.println("The states list: \n"+ states);
+		
+		// will throw IllegalArgumentException
+		List<String> statesSubList = states.subList(3, 1); 
+		
+		System.out.println("\nThe states sublist from index 1 (inclusive) to 3 (exclusive): \n"+ statesSubList);
+	}
+}

From b5ad31343eb192ca435c59945f64a74d3006635d Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Wed, 22 Dec 2021 21:09:24 +0530
Subject: [PATCH 11/31] Add blopost example for the removeIf, removeAll and
 isEmpty method of the arrayList in java

---
 .../ArrayListIsEmptyExample.java              | 44 +++++++++++++++++
 .../ArrayListRemoveAllExample.java            | 49 +++++++++++++++++++
 ...rrayListRemoveAllNullPointerException.java | 46 +++++++++++++++++
 .../ArrayListRemoveIfExample.java             | 37 ++++++++++++++
 4 files changed, 176 insertions(+)
 create mode 100644 collections/arraylist/arraylist-isempty-method/ArrayListIsEmptyExample.java
 create mode 100644 collections/arraylist/arraylist-removeall-method/ArrayListRemoveAllExample.java
 create mode 100644 collections/arraylist/arraylist-removeall-method/ArrayListRemoveAllNullPointerException.java
 create mode 100644 collections/arraylist/arraylist-removeif-method/ArrayListRemoveIfExample.java

diff --git a/collections/arraylist/arraylist-isempty-method/ArrayListIsEmptyExample.java b/collections/arraylist/arraylist-isempty-method/ArrayListIsEmptyExample.java
new file mode 100644
index 0000000..886e31e
--- /dev/null
+++ b/collections/arraylist/arraylist-isempty-method/ArrayListIsEmptyExample.java
@@ -0,0 +1,44 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+/**
+ * An example java program for an isEmpty method 
+ * of the ArrayList class in java.
+ * 
+ * @author Gaurav Kukade at coderolls
+ */
+public class ArrayListIsEmptyExample {
+
+	public static void main(String[] args) {
+		
+		// create an arraylyst teams
+		ArrayList<String> teams = new ArrayList<String>();
+		
+		// add elements to the arraylist teams
+		teams.add("LA Galaxy");
+		teams.add("Orlando City FC");
+		teams.add("Portland Timbers");
+		teams.add("Columbus Crew");
+		
+		boolean isTeamsEmpty = teams.isEmpty();
+		
+		if(isTeamsEmpty) {
+			System.out.println("Teams arraylist is empty.");
+		}
+		else {
+			System.out.println("Teams arraylist is not empty.");
+		}
+		
+		// create an arraylist players
+		ArrayList<String> players = new ArrayList<String>();
+		
+		boolean isPlayersEmpty = players.isEmpty();
+		
+		if(isPlayersEmpty) {
+			System.out.println("Players arraylist is empty.");
+		}
+		else {
+			System.out.println("Players arraylist is not empty.");
+		}
+	}
+}
diff --git a/collections/arraylist/arraylist-removeall-method/ArrayListRemoveAllExample.java b/collections/arraylist/arraylist-removeall-method/ArrayListRemoveAllExample.java
new file mode 100644
index 0000000..0033f0c
--- /dev/null
+++ b/collections/arraylist/arraylist-removeall-method/ArrayListRemoveAllExample.java
@@ -0,0 +1,49 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Predicate;
+
+/**
+ * A java program showing an example for the removeAll()
+ * method of the ArrayList class in Java.
+ * 
+ * @author gaurav
+ */
+public class ArrayListRemoveAllExample {
+
+	public static void main(String[] args) {
+
+		// create an empty arraylist object 'states'
+		List<String> states = new ArrayList<String>();
+
+		// add state in the arraylist, Florida multiple times
+		states.add("California");
+		states.add("Texas");
+		states.add("Montana");
+		states.add("Arizona");
+		states.add("Florida");
+		states.add("Michigan");
+		states.add("New Jersey");
+		states.add("Washington");
+		states.add("Ohio");
+		states.add("Minnesota");
+		states.add("Colorado");
+		states.add("Missouri");
+		states.add("Nevada");		
+		
+		// create another ArrayList for items to be removed
+		List<String> statesToBeRemoved = new ArrayList<String>();
+		statesToBeRemoved.add("Minnesota");
+		statesToBeRemoved.add("Missouri");
+		statesToBeRemoved.add("Montana");
+		statesToBeRemoved.add("Michigan");
+		
+		System.out.println("The states list before the removeAll() method call: \n" + states);
+		
+		// removes all elements specified in the ArrayList statesToBeRemoved 
+		states.removeAll(statesToBeRemoved); 
+		
+		System.out.println("\nThe states list after the removeAll() method call: \n" + states);
+	}
+}
diff --git a/collections/arraylist/arraylist-removeall-method/ArrayListRemoveAllNullPointerException.java b/collections/arraylist/arraylist-removeall-method/ArrayListRemoveAllNullPointerException.java
new file mode 100644
index 0000000..c6dbb56
--- /dev/null
+++ b/collections/arraylist/arraylist-removeall-method/ArrayListRemoveAllNullPointerException.java
@@ -0,0 +1,46 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Predicate;
+
+/**
+ * A java program showing a NullPointerException case 
+ * for the removeAll() method of the ArrayList class in Java.
+ * 
+ * @author gaurav
+ */
+public class ArrayListRemoveAllNullPointerException {
+
+	public static void main(String[] args) {
+
+		// create an empty arraylist object 'states'
+		List<String> states = new ArrayList<String>();
+
+		// add state in the arraylist, Florida multiple times
+		states.add("California");
+		states.add("Texas");
+		states.add("Montana");
+		states.add("Arizona");
+		states.add("Florida");
+		states.add("Michigan");
+		states.add("New Jersey");
+		states.add("Washington");
+		states.add("Ohio");
+		states.add("Minnesota");
+		states.add("Colorado");
+		states.add("Missouri");
+		states.add("Nevada");		
+		
+		// create another ArrayList with null value, 
+		//so that removeAll will throw NullPointerException
+		List<String> statesToBeRemoved =null;
+
+		System.out.println("The states list before the removeAll() method call: \n" + states);
+		
+		// removes all elements specified in the ArrayList statesToBeRemoved 
+		states.removeAll(statesToBeRemoved); 
+		
+		System.out.println("\nThe states list after the removeAll() method call: \n" + states);
+	}
+}
diff --git a/collections/arraylist/arraylist-removeif-method/ArrayListRemoveIfExample.java b/collections/arraylist/arraylist-removeif-method/ArrayListRemoveIfExample.java
new file mode 100644
index 0000000..27c0c29
--- /dev/null
+++ b/collections/arraylist/arraylist-removeif-method/ArrayListRemoveIfExample.java
@@ -0,0 +1,37 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Predicate;
+
+/**
+ * A java program showing an example for the removeIf()
+ * method of the ArrayList class in Java.
+ * 
+ * @author gaurav
+ */
+public class ArrayListRemoveIfExample {
+
+	public static void main(String[] args) {
+
+		// create an empty arraylist object 'states'
+		List<String> states = new ArrayList<String>();
+
+		// add state in the arraylist, Florida multiple times
+		states.add("California");
+		states.add("Texas");
+		states.add("Florida");
+		states.add("Florida");
+		states.add("New Jersey");
+		states.add("Washington");
+		states.add("Florida");
+
+		System.out.println("The states list before the removeIf() call: \n" + states);
+
+		// a predicate for the condition
+		Predicate p = s -> s.equals("Florida");
+		states.removeIf(p); // removes all elements which satisfy the predicate p
+
+		System.out.println("\nThe states list after the removeIf() call: \n" + states);
+	}
+}

From 2e3b92961f2a3bf05209b9bf3cd8cba718f58d89 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Fri, 24 Dec 2021 19:14:27 +0530
Subject: [PATCH 12/31] Add coding examples

---
 .../ArrayListEnsureCapacityExample.java       | 39 +++++++++++++++++++
 .../ArrayListListIteratorExample.java         | 35 +++++++++++++++++
 .../ArrayListListIteratorExample2.java        | 36 +++++++++++++++++
 .../ArrayListListIteratorException.java       | 36 +++++++++++++++++
 4 files changed, 146 insertions(+)
 create mode 100644 collections/arraylist/arraylist-ensurecapacity-method/ArrayListEnsureCapacityExample.java
 create mode 100644 collections/arraylist/arraylist-listiterator-method/ArrayListListIteratorExample.java
 create mode 100644 collections/arraylist/arraylist-listiterator-method/ArrayListListIteratorExample2.java
 create mode 100644 collections/arraylist/arraylist-listiterator-method/ArrayListListIteratorException.java

diff --git a/collections/arraylist/arraylist-ensurecapacity-method/ArrayListEnsureCapacityExample.java b/collections/arraylist/arraylist-ensurecapacity-method/ArrayListEnsureCapacityExample.java
new file mode 100644
index 0000000..e23fd9e
--- /dev/null
+++ b/collections/arraylist/arraylist-ensurecapacity-method/ArrayListEnsureCapacityExample.java
@@ -0,0 +1,39 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+/**
+ * An example java program for ensureCapacity(int MinCapacity) method 
+ * of the ArrayList class in java.
+ * @author Gaurav at coderolls.com
+ *
+ */
+public class ArrayListEnsureCapacityExample {
+
+	public static void main(String[] args) {
+		
+		// create an empty arraylist object 'states'
+		ArrayList<String> states = new ArrayList<>();
+
+		// add state in the arraylist
+		states.add("California");
+		states.add("Texas");
+		states.add("Montana");
+		states.add("Arizona");
+		states.add("Florida");
+		states.add("Michigan");
+		states.add("New Jersey");
+		states.add("Washington");
+		states.add("Ohio");
+		states.add("Minnesota");
+		states.add("Colorado");
+		states.add("Missouri");
+		states.add("Nevada");
+		System.out.println("ArrayList Elements are: \n"+ states);
+		//We need to add more states, so we will ensure 
+		//that arraylist should hold 50 elements
+		 states.ensureCapacity(50);
+		 
+		 System.out.println("\nWe ensured that the arraylist should hold 50 elements.");
+	}
+
+}
diff --git a/collections/arraylist/arraylist-listiterator-method/ArrayListListIteratorExample.java b/collections/arraylist/arraylist-listiterator-method/ArrayListListIteratorExample.java
new file mode 100644
index 0000000..d25c5b1
--- /dev/null
+++ b/collections/arraylist/arraylist-listiterator-method/ArrayListListIteratorExample.java
@@ -0,0 +1,35 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.ListIterator;
+/**
+ * An example java program about the listIterator()
+ * method of the arrayList.
+ * 
+ * @author coderolls.com
+ */
+public class ArrayListListIteratorExample {
+
+	public static void main(String[] args) {
+		
+		ArrayList<String> states = new ArrayList<>();
+
+		// add state in the arraylist
+		states.add("California");
+		states.add("Texas");
+		states.add("Montana");
+		states.add("Arizona");
+		states.add("Florida");
+		states.add("Michigan");
+		states.add("New Jersey");
+		states.add("Washington");
+		states.add("Ohio");
+		
+		ListIterator<String> itr = states.listIterator();
+		
+		while(itr.hasNext()) {
+			String state = itr.next();
+			System.out.println("The state :"+ state);
+		}
+	}
+}
diff --git a/collections/arraylist/arraylist-listiterator-method/ArrayListListIteratorExample2.java b/collections/arraylist/arraylist-listiterator-method/ArrayListListIteratorExample2.java
new file mode 100644
index 0000000..3f9c41e
--- /dev/null
+++ b/collections/arraylist/arraylist-listiterator-method/ArrayListListIteratorExample2.java
@@ -0,0 +1,36 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.ListIterator;
+/**
+ * An example java program about the listIterator()
+ * method of the arrayList.
+ * 
+ * @author coderolls.com
+ */
+public class ArrayListListIteratorExample2 {
+
+	public static void main(String[] args) {
+		
+		ArrayList<String> states = new ArrayList<>();
+
+		// add state in the arraylist
+		states.add("California");
+		states.add("Texas");
+		states.add("Montana");
+		states.add("Arizona");
+		states.add("Florida");
+		states.add("Michigan");
+		states.add("New Jersey");
+		states.add("Washington");
+		states.add("Ohio");
+		
+        //given index 3 iterator start from element with index 3
+		ListIterator<String> itr = states.listIterator(3);
+		
+		while(itr.hasNext()) {
+			String state = itr.next();
+			System.out.println("The state :"+ state);
+		}
+	}
+}
diff --git a/collections/arraylist/arraylist-listiterator-method/ArrayListListIteratorException.java b/collections/arraylist/arraylist-listiterator-method/ArrayListListIteratorException.java
new file mode 100644
index 0000000..a62a1cb
--- /dev/null
+++ b/collections/arraylist/arraylist-listiterator-method/ArrayListListIteratorException.java
@@ -0,0 +1,36 @@
+package com.gaurav.ExProject.ArrayList;
+
+import java.util.ArrayList;
+import java.util.ListIterator;
+/**
+ * An example java program about the listIterator()
+ * method of the arrayList.
+ * 
+ * @author coderolls.com
+ */
+public class ArrayListListIteratorException {
+
+	public static void main(String[] args) {
+		
+		ArrayList<String> states = new ArrayList<>();
+
+		// add state in the arraylist
+		states.add("California");
+		states.add("Texas");
+		states.add("Montana");
+		states.add("Arizona");
+		states.add("Florida");
+		states.add("Michigan");
+		states.add("New Jersey");
+		states.add("Washington");
+		states.add("Ohio");
+		
+        //given index 120, it will  throw IndexOutOfBoundsException
+		ListIterator<String> itr = states.listIterator(120);
+		
+		while(itr.hasNext()) {
+			String state = itr.next();
+			System.out.println("The state :"+ state);
+		}
+	}
+}

From 95ce3c4d0d149bed3273fb81033dc5000e8b0cb3 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Fri, 28 Jan 2022 17:40:13 +0530
Subject: [PATCH 13/31] Add LinkedList in java blog examples

---
 .../linkedlist/LinkedAllowDuplicates.java     | 25 +++++++++++++++++++
 collections/linkedlist/LinkedAllowNull.java   | 25 +++++++++++++++++++
 .../linkedlist/LinkedListInsertionOrder.java  | 22 ++++++++++++++++
 3 files changed, 72 insertions(+)
 create mode 100644 collections/linkedlist/LinkedAllowDuplicates.java
 create mode 100644 collections/linkedlist/LinkedAllowNull.java
 create mode 100644 collections/linkedlist/LinkedListInsertionOrder.java

diff --git a/collections/linkedlist/LinkedAllowDuplicates.java b/collections/linkedlist/LinkedAllowDuplicates.java
new file mode 100644
index 0000000..03b62bb
--- /dev/null
+++ b/collections/linkedlist/LinkedAllowDuplicates.java
@@ -0,0 +1,25 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+/**
+ * A Java program to prove that LinkedList Allows null values
+ * @author coderolls.com
+ *
+ */
+public class LinkedAllowDuplicates {
+
+	public static void main(String[] args) {
+
+		LinkedList<String> linkedList = new LinkedList<String>();
+		linkedList.add("John");
+		linkedList.add(null);
+		linkedList.add("Mark");
+		linkedList.add(null);
+		linkedList.add("Ruby");
+		linkedList.add("Lucy");
+		linkedList.add("Vikram");
+		linkedList.add(null);
+		
+		System.out.println(linkedList);
+	}
+}
diff --git a/collections/linkedlist/LinkedAllowNull.java b/collections/linkedlist/LinkedAllowNull.java
new file mode 100644
index 0000000..a26f0dd
--- /dev/null
+++ b/collections/linkedlist/LinkedAllowNull.java
@@ -0,0 +1,25 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+/**
+ * A Java program to prove that LinkedList Allows Duplicates
+ * @author coderolls.com
+ *
+ */
+public class LinkedAllowNull {
+
+	public static void main(String[] args) {
+
+		LinkedList<String> linkedList = new LinkedList<String>();
+		linkedList.add("John");
+		linkedList.add("Mark");
+		linkedList.add("Mark");
+		linkedList.add("Mark");
+		linkedList.add("Ruby");
+		linkedList.add("Lucy");
+		linkedList.add("Vikram");
+		linkedList.add("Vikram");
+		
+		System.out.println(linkedList);
+	}
+}
diff --git a/collections/linkedlist/LinkedListInsertionOrder.java b/collections/linkedlist/LinkedListInsertionOrder.java
new file mode 100644
index 0000000..14007ae
--- /dev/null
+++ b/collections/linkedlist/LinkedListInsertionOrder.java
@@ -0,0 +1,22 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+/**
+ * A Java program to prove that LinkedList maintains insertion order
+ * @author coderolls.com
+ *
+ */
+public class LinkedListInsertionOrder {
+
+	public static void main(String[] args) {
+
+		LinkedList<String> linkedList = new LinkedList<String>();
+		linkedList.add("John");
+		linkedList.add("Mark");
+		linkedList.add("Ruby");
+		linkedList.add("Lucy");
+		linkedList.add("Vikram");
+		
+		System.out.println(linkedList);
+	}
+}

From 1d58ac2e3c4092983348405b87c2eabafe646a1a Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Fri, 28 Jan 2022 17:42:06 +0530
Subject: [PATCH 14/31] Add LinkedList in java blog examples

---
 .../{ => linkedlist-in-java}/LinkedAllowDuplicates.java           | 0
 .../linkedlist/{ => linkedlist-in-java}/LinkedAllowNull.java      | 0
 .../{ => linkedlist-in-java}/LinkedListInsertionOrder.java        | 0
 3 files changed, 0 insertions(+), 0 deletions(-)
 rename collections/linkedlist/{ => linkedlist-in-java}/LinkedAllowDuplicates.java (100%)
 rename collections/linkedlist/{ => linkedlist-in-java}/LinkedAllowNull.java (100%)
 rename collections/linkedlist/{ => linkedlist-in-java}/LinkedListInsertionOrder.java (100%)

diff --git a/collections/linkedlist/LinkedAllowDuplicates.java b/collections/linkedlist/linkedlist-in-java/LinkedAllowDuplicates.java
similarity index 100%
rename from collections/linkedlist/LinkedAllowDuplicates.java
rename to collections/linkedlist/linkedlist-in-java/LinkedAllowDuplicates.java
diff --git a/collections/linkedlist/LinkedAllowNull.java b/collections/linkedlist/linkedlist-in-java/LinkedAllowNull.java
similarity index 100%
rename from collections/linkedlist/LinkedAllowNull.java
rename to collections/linkedlist/linkedlist-in-java/LinkedAllowNull.java
diff --git a/collections/linkedlist/LinkedListInsertionOrder.java b/collections/linkedlist/linkedlist-in-java/LinkedListInsertionOrder.java
similarity index 100%
rename from collections/linkedlist/LinkedListInsertionOrder.java
rename to collections/linkedlist/linkedlist-in-java/LinkedListInsertionOrder.java

From db4e4095ed4bb86609afc41f77ac453e2c28c1a3 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Fri, 28 Jan 2022 17:45:12 +0530
Subject: [PATCH 15/31] Add and update README.md for linkedlist

---
 collections/linkedlist/README.md | 9 +++++++++
 1 file changed, 9 insertions(+)
 create mode 100644 collections/linkedlist/README.md

diff --git a/collections/linkedlist/README.md b/collections/linkedlist/README.md
new file mode 100644
index 0000000..c2945f3
--- /dev/null
+++ b/collections/linkedlist/README.md
@@ -0,0 +1,9 @@
+# Java Collections - LinkedList in Java
+
+This module contains articles related to LinkedList in Java.
+
+## Related articles
+
+- [LinkedList In Java](https://coderolls.com/linkedlist-in-java/)
+
+Visit [coderolls](https://coderolls.com/) to read more tutorials.

From 8f0441c0c972f54791905746450a74bbc33a1196 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Thu, 3 Feb 2022 18:31:01 +0530
Subject: [PATCH 16/31] Add linkedlist addfirst method example

---
 .../LinkedListAddFirst.java                   | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 collections/linkedlist/linkedlist-addfirst-method/LinkedListAddFirst.java

diff --git a/collections/linkedlist/linkedlist-addfirst-method/LinkedListAddFirst.java b/collections/linkedlist/linkedlist-addfirst-method/LinkedListAddFirst.java
new file mode 100644
index 0000000..bdcc85d
--- /dev/null
+++ b/collections/linkedlist/linkedlist-addfirst-method/LinkedListAddFirst.java
@@ -0,0 +1,24 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+public class LinkedListAddFirst {
+
+	public static void main(String[] args) {
+	
+		LinkedList<String> linkedList = new LinkedList<String>();
+		linkedList.add("Austin");
+		linkedList.add("Boston");
+		linkedList.add("Atlanta");
+		linkedList.add("Madison");
+		linkedList.add("Columbia");
+		
+		System.out.println(linkedList);
+		
+		// add element at the beginning
+		linkedList.addFirst("Albany");
+		System.out.println(linkedList);
+
+	}
+
+}

From 08e365550a5ffa625c7e0e15804f9ab26939f1e3 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Thu, 3 Feb 2022 18:56:21 +0530
Subject: [PATCH 17/31] Add linkedlist addlast method example

---
 .../LinkedListAddLast.java                    | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)
 create mode 100644 collections/linkedlist/linkedlist-addlast-method/LinkedListAddLast.java

diff --git a/collections/linkedlist/linkedlist-addlast-method/LinkedListAddLast.java b/collections/linkedlist/linkedlist-addlast-method/LinkedListAddLast.java
new file mode 100644
index 0000000..30fec6f
--- /dev/null
+++ b/collections/linkedlist/linkedlist-addlast-method/LinkedListAddLast.java
@@ -0,0 +1,24 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+public class LinkedListAddLast {
+
+	public static void main(String[] args) {
+	
+		LinkedList<String> linkedList = new LinkedList<String>();
+		linkedList.add("Austin");
+		linkedList.add("Boston");
+		linkedList.add("Atlanta");
+		linkedList.add("Madison");
+		linkedList.add("Columbia");
+		
+		System.out.println(linkedList);
+		
+		// add element at the end
+		linkedList.addLast("Albany");
+		System.out.println(linkedList);
+
+	}
+
+}

From 15f92a195eff0707fce9026fbf985163051cab5b Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Fri, 4 Feb 2022 14:44:29 +0530
Subject: [PATCH 18/31] Add linkedlist to array example

---
 .../LinkedListToArray.java                    | 36 +++++++++++++++++++
 .../LinkedListToArray2.java                   | 36 +++++++++++++++++++
 2 files changed, 72 insertions(+)
 create mode 100644 collections/linkedlist/convert-linkedlist-to-array/LinkedListToArray.java
 create mode 100644 collections/linkedlist/convert-linkedlist-to-array/LinkedListToArray2.java

diff --git a/collections/linkedlist/convert-linkedlist-to-array/LinkedListToArray.java b/collections/linkedlist/convert-linkedlist-to-array/LinkedListToArray.java
new file mode 100644
index 0000000..e3d4365
--- /dev/null
+++ b/collections/linkedlist/convert-linkedlist-to-array/LinkedListToArray.java
@@ -0,0 +1,36 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A java program to convert linkedlist to an array
+ * using the toArray() method.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListToArray {
+
+	public static void main(String[] args) {
+
+		LinkedList<String> linkedList = new LinkedList<String>();
+		linkedList.add("Walmart");
+		linkedList.add("Amazon");
+		linkedList.add("Apple");
+		linkedList.add("Microsoft");
+		linkedList.add("Google");
+		linkedList.add("Uber");
+		linkedList.add("Tesla");
+		
+		System.out.println("Printing the linkedList: ");
+		System.out.println(linkedList);
+		
+		// convert linkedList to Object[]
+		Object[] arr = linkedList.toArray();
+		
+		System.out.println("\nPrinting the object array elements: ");
+		for(Object obj:arr) {
+			System.out.println(obj.toString());
+		}
+	}
+}
diff --git a/collections/linkedlist/convert-linkedlist-to-array/LinkedListToArray2.java b/collections/linkedlist/convert-linkedlist-to-array/LinkedListToArray2.java
new file mode 100644
index 0000000..12203c4
--- /dev/null
+++ b/collections/linkedlist/convert-linkedlist-to-array/LinkedListToArray2.java
@@ -0,0 +1,36 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A java program to convert linkedlist to an array
+ * using the toArray(T[] a) method.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListToArray2 {
+
+	public static void main(String[] args) {
+
+		LinkedList<String> linkedList = new LinkedList<String>();
+		linkedList.add("Walmart");
+		linkedList.add("Amazon");
+		linkedList.add("Apple");
+		linkedList.add("Microsoft");
+		linkedList.add("Google");
+		linkedList.add("Uber");
+		linkedList.add("Tesla");
+		
+		System.out.println("Printing the linkedList: ");
+		System.out.println(linkedList);
+		
+		// convert linkedList to String array
+		String[] arr = linkedList.toArray(new String[linkedList.size()]);
+		
+		System.out.println("\nPrinting the String array elements: ");
+		for(String str:arr) {
+			System.out.println(str);
+		}
+	}
+}

From 4b14095e34af92812a1d15972d7eb9a46f5a4c30 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Sat, 5 Feb 2022 12:28:20 +0530
Subject: [PATCH 19/31] Add example for add element to the linkedlist

---
 .../LinkedListAddExample.java                 | 32 ++++++++++++++++++
 .../LinkedListAddExample2.java                | 33 +++++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 collections/linkedlist/add-element-in-linkedlist/LinkedListAddExample.java
 create mode 100644 collections/linkedlist/add-element-in-linkedlist/LinkedListAddExample2.java

diff --git a/collections/linkedlist/add-element-in-linkedlist/LinkedListAddExample.java b/collections/linkedlist/add-element-in-linkedlist/LinkedListAddExample.java
new file mode 100644
index 0000000..13ce6f9
--- /dev/null
+++ b/collections/linkedlist/add-element-in-linkedlist/LinkedListAddExample.java
@@ -0,0 +1,32 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to add an element to the LinkedList.
+ * 
+ * The add(E e) method will add an element to 
+ * the end of the linkedList.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListAddExample {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		
+		//adding elements to the linkedList
+		linkedList.add("John");
+		linkedList.add("Peter");
+		
+		System.out.println(linkedList);// [John, Peter]
+		
+		// adding an element to the linkedList
+		// element will be added to the end of the linkedList
+		linkedList.add("Noah");
+		
+		System.out.println(linkedList); // [John, Peter, Noah]
+	}
+}
diff --git a/collections/linkedlist/add-element-in-linkedlist/LinkedListAddExample2.java b/collections/linkedlist/add-element-in-linkedlist/LinkedListAddExample2.java
new file mode 100644
index 0000000..978faad
--- /dev/null
+++ b/collections/linkedlist/add-element-in-linkedlist/LinkedListAddExample2.java
@@ -0,0 +1,33 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to add an element to the linkedlist
+ * at the specific index.
+ * 
+ * The add(int index, E element) method will add 
+ * an element at the specified index in LinkedList.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListAddExample2 {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		
+		//adding elements to the linkedList using normal add method
+		linkedList.add("John");
+		linkedList.add("Peter");
+        linkedList.add("Karan");
+		
+		System.out.println(linkedList);// [John, Peter, Karan]
+		
+		// adding an element to  the LinkedList at index 1
+		linkedList.add(1, "Noah");
+		
+		System.out.println(linkedList); // [John, Noah, Peter, Karan]
+	}
+}
\ No newline at end of file

From 5f14b90ce38d436a9f14fb3af39940344959b415 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Tue, 8 Feb 2022 19:10:33 +0530
Subject: [PATCH 20/31] Add examples for remove an element form linkedlist
 blogpost

---
 .../LinkedListRemove.java                     | 33 +++++++++++++++++++
 .../LinkedListRemoveFirst.java                | 33 +++++++++++++++++++
 .../LinkedListRemoveLast.java                 | 33 +++++++++++++++++++
 .../LinkedListRemoveObject.java               | 33 +++++++++++++++++++
 .../LinkedListRemoveObjectByIndex.java        | 32 ++++++++++++++++++
 5 files changed, 164 insertions(+)
 create mode 100644 collections/linkedlist/remove-element-from-linkedlist/LinkedListRemove.java
 create mode 100644 collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveFirst.java
 create mode 100644 collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveLast.java
 create mode 100644 collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveObject.java
 create mode 100644 collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveObjectByIndex.java

diff --git a/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemove.java b/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemove.java
new file mode 100644
index 0000000..4c3e3a2
--- /dev/null
+++ b/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemove.java
@@ -0,0 +1,33 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to remove head element from 
+ * the linkedList using the remove() method.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListRemove {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		
+		linkedList.add("BHIM");
+		linkedList.add("PayTM");
+		linkedList.add("Freecharge");
+		linkedList.add("PhonePe");
+		linkedList.add("JioPay");
+		
+		System.out.println("LinkedList before removing an element:");
+		System.out.println(linkedList);
+		
+		// removes head(first element) i.e. removes BHIM
+		linkedList.remove();
+		
+		System.out.println("\nLinkedList after removing an element using remove() method:");
+		System.out.println(linkedList);
+	}
+}
diff --git a/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveFirst.java b/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveFirst.java
new file mode 100644
index 0000000..116fbff
--- /dev/null
+++ b/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveFirst.java
@@ -0,0 +1,33 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to remove first element from 
+ * the linkedList using the removeFirst() method.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListRemoveFirst {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		
+		linkedList.add("BHIM");
+		linkedList.add("PayTM");
+		linkedList.add("Freecharge");
+		linkedList.add("PhonePe");
+		linkedList.add("JioPay");
+		
+		System.out.println("LinkedList before removing an element:");
+		System.out.println(linkedList);
+		
+		// removes first element i.e. removes BHIM
+		linkedList.removeFirst();
+		
+		System.out.println("\nLinkedList after removing an element using removeFirst() method:");
+		System.out.println(linkedList);
+	}
+}
diff --git a/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveLast.java b/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveLast.java
new file mode 100644
index 0000000..048b98a
--- /dev/null
+++ b/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveLast.java
@@ -0,0 +1,33 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to remove last element from 
+ * the linkedList using the removeLast() method.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListRemoveLast {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		
+		linkedList.add("BHIM");
+		linkedList.add("PayTM");
+		linkedList.add("Freecharge");
+		linkedList.add("PhonePe");
+		linkedList.add("JioPay");
+		
+		System.out.println("LinkedList before removing an element:");
+		System.out.println(linkedList);
+		
+		// removes first element i.e. removes BHIM
+		linkedList.removeLast();
+		
+		System.out.println("\nLinkedList after removing an element using removeLast() method:");
+		System.out.println(linkedList);
+	}
+}
diff --git a/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveObject.java b/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveObject.java
new file mode 100644
index 0000000..53ac935
--- /dev/null
+++ b/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveObject.java
@@ -0,0 +1,33 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to remove the specified element from 
+ * the linkedList using the remove(Object o) method.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListRemoveObject {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		
+		linkedList.add("BHIM");
+		linkedList.add("PayTM");
+		linkedList.add("Freecharge");
+		linkedList.add("PhonePe");
+		linkedList.add("JioPay");
+		
+		System.out.println("LinkedList before removing an element:");
+		System.out.println(linkedList);
+		
+		// removes the specified element i.e. removes Freecharge
+		linkedList.remove("Freecharge");
+		
+		System.out.println("\nLinkedList after removing an element using remove(Object o) method:");
+		System.out.println(linkedList);
+	}
+}
diff --git a/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveObjectByIndex.java b/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveObjectByIndex.java
new file mode 100644
index 0000000..23da316
--- /dev/null
+++ b/collections/linkedlist/remove-element-from-linkedlist/LinkedListRemoveObjectByIndex.java
@@ -0,0 +1,32 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to remove element at the specified position i.e. index
+ * from the linkedList using the remove(int index) method.
+ * 
+ * @author coderolls.com
+ */
+public class LinkedListRemoveObjectByIndex {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		
+		linkedList.add("BHIM");
+		linkedList.add("PayTM");
+		linkedList.add("Freecharge");
+		linkedList.add("PhonePe");
+		linkedList.add("JioPay");
+		
+		System.out.println("LinkedList before removing an element:");
+		System.out.println(linkedList);
+		
+		// removes the element at index 3 i.e. removes PhonePe
+		linkedList.remove(3);
+		
+		System.out.println("\nLinkedList after removing an element using remove(int index) method:");
+		System.out.println(linkedList);
+	}
+}

From 5d1164c61d7bbcc133fd4e9dffc18b1569c48ecd Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Wed, 9 Feb 2022 08:20:28 +0530
Subject: [PATCH 21/31] Add example for LinkedList contains() method

---
 .../LinkedListContains.java                   | 40 +++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 collections/linkedlist/check-if-linkedlist-contains-an-element/LinkedListContains.java

diff --git a/collections/linkedlist/check-if-linkedlist-contains-an-element/LinkedListContains.java b/collections/linkedlist/check-if-linkedlist-contains-an-element/LinkedListContains.java
new file mode 100644
index 0000000..4fb2e0b
--- /dev/null
+++ b/collections/linkedlist/check-if-linkedlist-contains-an-element/LinkedListContains.java
@@ -0,0 +1,40 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to check if the element is present 
+ * in the linkedList using the contains(Object o) method.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListContains {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		
+		linkedList.add("Uber");
+		linkedList.add("Ola");
+		linkedList.add("Didi");
+		linkedList.add("Lyft");
+		linkedList.add("Yandex");
+		
+		System.out.println("LinkedList is as follows: \n"+ linkedList);
+
+		
+		// checks if the linkedList contains "Ola"
+		// returns true if present
+		boolean isOlaPresnet = linkedList.contains("Ola"); // true
+		
+		System.out.println("\nCheck if linkedList contains Ola: "+ isOlaPresnet);
+
+		// checks if the linkedList contains "Grab"
+		// returns true if present
+		boolean isGrabPresnet = linkedList.contains("Grab"); // false
+		
+		System.out.println("\nCheck if linkedList contains Grab: "+ isGrabPresnet);
+		
+	}
+}

From 6011fa4808f1e4c582f37264c9de5dcf109bcae5 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Thu, 10 Feb 2022 16:34:09 +0530
Subject: [PATCH 22/31] Add get element from linkedlist example

---
 .../LinkedListGetElement.java                 | 30 +++++++++++++++++++
 .../LinkedListGetFirst.java                   | 30 +++++++++++++++++++
 .../LinkedListGetLast.java                    | 30 +++++++++++++++++++
 3 files changed, 90 insertions(+)
 create mode 100644 collections/linkedlist/get-an-element-from-linkedlist/LinkedListGetElement.java
 create mode 100644 collections/linkedlist/get-an-element-from-linkedlist/LinkedListGetFirst.java
 create mode 100644 collections/linkedlist/get-an-element-from-linkedlist/LinkedListGetLast.java

diff --git a/collections/linkedlist/get-an-element-from-linkedlist/LinkedListGetElement.java b/collections/linkedlist/get-an-element-from-linkedlist/LinkedListGetElement.java
new file mode 100644
index 0000000..62fe1b9
--- /dev/null
+++ b/collections/linkedlist/get-an-element-from-linkedlist/LinkedListGetElement.java
@@ -0,0 +1,30 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to get an element from
+ * the linkedlist by it's index.
+ * 
+ * @author coderolls.com
+ */
+public class LinkedListGetElement {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		linkedList.add("Adidas");
+		linkedList.add("Air");
+		linkedList.add("Nike");
+		linkedList.add("Puma");
+		linkedList.add("Reebok");
+		
+		System.out.println("LinkedList: ");
+		System.out.println(linkedList);
+		
+		// get element at index 3
+		String element = linkedList.get(3); // Puma
+		
+		System.out.println("\nElement at index 3 is: "+ element);
+	}
+}
diff --git a/collections/linkedlist/get-an-element-from-linkedlist/LinkedListGetFirst.java b/collections/linkedlist/get-an-element-from-linkedlist/LinkedListGetFirst.java
new file mode 100644
index 0000000..883797e
--- /dev/null
+++ b/collections/linkedlist/get-an-element-from-linkedlist/LinkedListGetFirst.java
@@ -0,0 +1,30 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to get the first element from
+ * the linkedlist using getFirst() method.
+ * 
+ * @author coderolls.com
+ */
+public class LinkedListGetFirst {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		linkedList.add("Adidas");
+		linkedList.add("Air");
+		linkedList.add("Nike");
+		linkedList.add("Puma");
+		linkedList.add("Reebok");
+		
+		System.out.println("LinkedList: ");
+		System.out.println(linkedList);
+		
+		// get first element
+		String element = linkedList.getFirst(); // Adidas
+		
+		System.out.println("\nFirst element of the linkedList is: "+ element);
+	}
+}
diff --git a/collections/linkedlist/get-an-element-from-linkedlist/LinkedListGetLast.java b/collections/linkedlist/get-an-element-from-linkedlist/LinkedListGetLast.java
new file mode 100644
index 0000000..a72f44e
--- /dev/null
+++ b/collections/linkedlist/get-an-element-from-linkedlist/LinkedListGetLast.java
@@ -0,0 +1,30 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to get the last element of
+ * the linkedlist using getLast() method.
+ * 
+ * @author coderolls.com
+ */
+public class LinkedListGetLast {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		linkedList.add("Adidas");
+		linkedList.add("Air");
+		linkedList.add("Nike");
+		linkedList.add("Puma");
+		linkedList.add("Reebok");
+		
+		System.out.println("LinkedList: ");
+		System.out.println(linkedList);
+		
+		// get first element
+		String element = linkedList.getLast(); // Adidas
+		
+		System.out.println("\nLast element of the linkedList is: "+ element);
+	}
+}

From 5837e94432f912a026ff51b6e1e122ea2a8014ba Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Thu, 10 Feb 2022 20:12:01 +0530
Subject: [PATCH 23/31] Add example for get an index of element from linkedlist
 blog

---
 .../LinkedListIndexOf.java                    | 38 +++++++++++++++++++
 .../LinkedListLastIndexOf.java                | 38 +++++++++++++++++++
 2 files changed, 76 insertions(+)
 create mode 100644 collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListIndexOf.java
 create mode 100644 collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListLastIndexOf.java

diff --git a/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListIndexOf.java b/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListIndexOf.java
new file mode 100644
index 0000000..98df49f
--- /dev/null
+++ b/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListIndexOf.java
@@ -0,0 +1,38 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to get the first index of the element from
+ * the linkedlist using indexOf(Object o) method.
+ * 
+ * @author coderolls.com
+ */
+public class LinkedListIndexOf {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		linkedList.add("PepsiCo");
+		linkedList.add("DrPepper");
+		linkedList.add("GoldSpot");
+		linkedList.add("GoldSpot");
+		linkedList.add("CocaCola");
+		linkedList.add("Moxie");
+		linkedList.add("GoldSpot");
+		linkedList.add("Moxie");
+		
+		System.out.println("LinkedList: ");
+		System.out.println(linkedList);
+		
+		// get first index of GoldSpot
+		int index = linkedList.indexOf("GoldSpot"); // 2
+		
+		System.out.println("\nIndex of the GoldSpot in linkedList is: "+ index);
+		
+		// get first index of Moxie
+		int indexMoxie = linkedList.indexOf("Moxie"); // 5
+		
+		System.out.println("\nIndex of the Moxie in linkedList is: "+ indexMoxie);
+	}
+}
diff --git a/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListLastIndexOf.java b/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListLastIndexOf.java
new file mode 100644
index 0000000..6d3f3a1
--- /dev/null
+++ b/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListLastIndexOf.java
@@ -0,0 +1,38 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A Java program to get the last index of the element from
+ * the linkedlist using lastIndexOf(Object o) method.
+ * 
+ * @author coderolls.com
+ */
+public class LinkedListLastIndexOf {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> linkedList = new LinkedList<String>();
+		linkedList.add("PepsiCo");
+		linkedList.add("DrPepper");
+		linkedList.add("GoldSpot");
+		linkedList.add("GoldSpot");
+		linkedList.add("CocaCola");
+		linkedList.add("Moxie");
+		linkedList.add("GoldSpot");
+		linkedList.add("Moxie");
+		
+		System.out.println("LinkedList: ");
+		System.out.println(linkedList);
+		
+		// get first index of GoldSpot
+		int index = linkedList.lastIndexOf("GoldSpot"); // 6
+		
+		System.out.println("\nIndex of the GoldSpot in linkedList is: "+ index);
+		
+		// get first index of Moxie
+		int indexMoxie = linkedList.lastIndexOf("Moxie"); // 7
+		
+		System.out.println("\nIndex of the Moxie in linkedList is: "+ indexMoxie);
+	}
+}

From 7d76ced3b76a98b18167f907e51ede8dda4c96d5 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Thu, 10 Feb 2022 20:13:17 +0530
Subject: [PATCH 24/31] Add example for get an index of element from linkedlist
 blog

---
 .../LinkedListLastIndexOf.java                                | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListLastIndexOf.java b/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListLastIndexOf.java
index 6d3f3a1..6d8b452 100644
--- a/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListLastIndexOf.java
+++ b/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListLastIndexOf.java
@@ -25,12 +25,12 @@ public static void main(String[] args) {
 		System.out.println("LinkedList: ");
 		System.out.println(linkedList);
 		
-		// get first index of GoldSpot
+		// get last index of GoldSpot
 		int index = linkedList.lastIndexOf("GoldSpot"); // 6
 		
 		System.out.println("\nIndex of the GoldSpot in linkedList is: "+ index);
 		
-		// get first index of Moxie
+		// get last index of Moxie
 		int indexMoxie = linkedList.lastIndexOf("Moxie"); // 7
 		
 		System.out.println("\nIndex of the Moxie in linkedList is: "+ indexMoxie);

From 49c4ee20da18a6da5dbf406f939c803b6cec5a63 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Fri, 11 Feb 2022 05:52:00 +0530
Subject: [PATCH 25/31] Updated blogpost example

---
 .../LinkedListIndexOf.java                            |  9 +++++++--
 .../LinkedListLastIndexOf.java                        | 11 ++++++++---
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListIndexOf.java b/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListIndexOf.java
index 98df49f..aad7aaf 100644
--- a/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListIndexOf.java
+++ b/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListIndexOf.java
@@ -26,9 +26,14 @@ public static void main(String[] args) {
 		System.out.println(linkedList);
 		
 		// get first index of GoldSpot
-		int index = linkedList.indexOf("GoldSpot"); // 2
+		int index = linkedList.indexOf("DrPepper"); // 1
 		
-		System.out.println("\nIndex of the GoldSpot in linkedList is: "+ index);
+		System.out.println("\nIndex of the DrPepper in linkedList is: "+ index);
+		
+		// get first index of GoldSpot
+		int indexGS = linkedList.indexOf("GoldSpot"); // 2
+		
+		System.out.println("\nIndex of the GoldSpot in linkedList is: "+ indexGS);
 		
 		// get first index of Moxie
 		int indexMoxie = linkedList.indexOf("Moxie"); // 5
diff --git a/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListLastIndexOf.java b/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListLastIndexOf.java
index 6d8b452..b15b3ff 100644
--- a/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListLastIndexOf.java
+++ b/collections/linkedlist/get-an-index-of-element-of-linkedlist/LinkedListLastIndexOf.java
@@ -26,13 +26,18 @@ public static void main(String[] args) {
 		System.out.println(linkedList);
 		
 		// get last index of GoldSpot
-		int index = linkedList.lastIndexOf("GoldSpot"); // 6
+		int index = linkedList.lastIndexOf("DrPepper"); // 1
 		
-		System.out.println("\nIndex of the GoldSpot in linkedList is: "+ index);
+		System.out.println("\nLast index of the DrPepper in linkedList is: "+ index);
+		
+		// get last index of GoldSpot
+		int indexGS = linkedList.lastIndexOf("GoldSpot"); // 6
+		
+		System.out.println("\nLast index of the GoldSpot in linkedList is: "+ indexGS);
 		
 		// get last index of Moxie
 		int indexMoxie = linkedList.lastIndexOf("Moxie"); // 7
 		
-		System.out.println("\nIndex of the Moxie in linkedList is: "+ indexMoxie);
+		System.out.println("\nLast index of the Moxie in linkedList is: "+ indexMoxie);
 	}
 }

From bad40426aafc80fb3556d9a83a22d2939b171fb9 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Tue, 15 Feb 2022 11:40:17 +0530
Subject: [PATCH 26/31] Add linkedlist set method example

---
 .../LinkedListSet.java                        | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 collections/linkedlist/set-element-at-an-index-in-linkedlist/LinkedListSet.java

diff --git a/collections/linkedlist/set-element-at-an-index-in-linkedlist/LinkedListSet.java b/collections/linkedlist/set-element-at-an-index-in-linkedlist/LinkedListSet.java
new file mode 100644
index 0000000..251898b
--- /dev/null
+++ b/collections/linkedlist/set-element-at-an-index-in-linkedlist/LinkedListSet.java
@@ -0,0 +1,36 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+
+/**
+ * A java program to set an element at specified index
+ * using the set(int index, E element) method.
+ * 
+ * @author coderolls.com
+ */
+public class LinkedListSet {
+
+	public static void main(String[] args) {
+		LinkedList<String> linkedList = new LinkedList<String>();
+		
+		linkedList.add("IN");
+		linkedList.add("US");
+		linkedList.add("FR");
+		linkedList.add("JP");
+		linkedList.add("CN");
+		linkedList.add("RU");
+		
+		System.out.println("LinkedList before setting an element at index 4:");
+		System.out.println(linkedList);
+		
+		// replaces CN with BR 
+		// returns the previously present element at index 4 i.e CN
+		String previousElement = linkedList.set(4, "BR");
+		
+		System.out.println("\nLinkedList after setting an element BR at index 4:");
+		System.out.println(linkedList);
+		
+		System.out.println("\nPreviously present element at index 4:");
+		System.out.println(previousElement);
+	}
+}

From 4677defd1e5725dab6b454b6db65e800328257ba Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Wed, 16 Feb 2022 14:23:52 +0530
Subject: [PATCH 27/31] Add iterate linkedlist example

---
 .../LinkedListForEachMethod.java              | 30 +++++++++++++
 .../LinkedListForLoop.java                    | 38 ++++++++++++++++
 .../LinkedListForeachLoop.java                | 33 ++++++++++++++
 .../LinkedListIterator.java                   | 37 ++++++++++++++++
 .../LinkedListWhileLoop.java                  | 44 +++++++++++++++++++
 5 files changed, 182 insertions(+)
 create mode 100644 collections/linkedlist/iterate-linkedlist-in-java/LinkedListForEachMethod.java
 create mode 100644 collections/linkedlist/iterate-linkedlist-in-java/LinkedListForLoop.java
 create mode 100644 collections/linkedlist/iterate-linkedlist-in-java/LinkedListForeachLoop.java
 create mode 100644 collections/linkedlist/iterate-linkedlist-in-java/LinkedListIterator.java
 create mode 100644 collections/linkedlist/iterate-linkedlist-in-java/LinkedListWhileLoop.java

diff --git a/collections/linkedlist/iterate-linkedlist-in-java/LinkedListForEachMethod.java b/collections/linkedlist/iterate-linkedlist-in-java/LinkedListForEachMethod.java
new file mode 100644
index 0000000..f9889c4
--- /dev/null
+++ b/collections/linkedlist/iterate-linkedlist-in-java/LinkedListForEachMethod.java
@@ -0,0 +1,30 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * A java program to iterate over linkedList
+ * using the java 8 foreach method.
+ * 
+ * @author coderolls.com
+ */
+public class LinkedListForEachMethod {
+
+	public static void main(String[] args) {
+
+		List<String> linkedList = new LinkedList<String>();
+
+		linkedList.add("Mango");
+		linkedList.add("Banana");
+		linkedList.add("Grapes");
+		linkedList.add("Watermelon");
+		linkedList.add("Apple");
+		linkedList.add("Avocado");
+
+		System.out.println("Iterating through LinkedList using forEach method and lamda expression........\n");
+
+		// add lambda expression in the foreach method
+		linkedList.forEach(s -> System.out.println("Object form the LinkedList is " + s));
+	}
+}
diff --git a/collections/linkedlist/iterate-linkedlist-in-java/LinkedListForLoop.java b/collections/linkedlist/iterate-linkedlist-in-java/LinkedListForLoop.java
new file mode 100644
index 0000000..92428da
--- /dev/null
+++ b/collections/linkedlist/iterate-linkedlist-in-java/LinkedListForLoop.java
@@ -0,0 +1,38 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * A java program to iterate over linkedList
+ * using the basic for loop.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListForLoop {
+
+	public static void main(String[] args) {
+
+		List<String> linkedList = new LinkedList<String>();
+
+		linkedList.add("Mango");
+		linkedList.add("Banana");
+		linkedList.add("Grapes");
+		linkedList.add("Watermelon");
+		linkedList.add("Apple");
+		linkedList.add("Avocado");
+
+		System.out.println("Iterating through LinkedList using the basic for loop!\n");
+		
+		int len = linkedList.size();
+		
+		// iterate over linkedList using basic for loop
+		for (int i = 0; i < len; i++) {
+			
+			// get String object from linkedList at index i
+			String str = linkedList.get(i);
+			System.out.println("Object form the LinkedList at " + i + " is " + str);
+		}
+	}
+}
diff --git a/collections/linkedlist/iterate-linkedlist-in-java/LinkedListForeachLoop.java b/collections/linkedlist/iterate-linkedlist-in-java/LinkedListForeachLoop.java
new file mode 100644
index 0000000..cd4f7eb
--- /dev/null
+++ b/collections/linkedlist/iterate-linkedlist-in-java/LinkedListForeachLoop.java
@@ -0,0 +1,33 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * A java program to iterate over linkedList
+ * using the foreach loop.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListForeachLoop {
+
+	public static void main(String[] args) {
+
+		List<String> linkedList = new LinkedList<String>();
+
+		linkedList.add("Mango");
+		linkedList.add("Banana");
+		linkedList.add("Grapes");
+		linkedList.add("Watermelon");
+		linkedList.add("Apple");
+		linkedList.add("Avocado");
+
+		System.out.println("Iterating through LinkedList using the foreach loop!\n");
+		
+		// iterate over linkedList using foreach loop
+		for (String str: linkedList) {
+			System.out.println("Object form the LinkedList is "+str);
+		}
+	}
+}
diff --git a/collections/linkedlist/iterate-linkedlist-in-java/LinkedListIterator.java b/collections/linkedlist/iterate-linkedlist-in-java/LinkedListIterator.java
new file mode 100644
index 0000000..163e27a
--- /dev/null
+++ b/collections/linkedlist/iterate-linkedlist-in-java/LinkedListIterator.java
@@ -0,0 +1,37 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * A java program to iterate through LinkedList using Iterator interface.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListIterator {
+
+	public static void main(String[] args) {
+		List<String> linkedList = new LinkedList<String>();
+
+		linkedList.add("Mango");
+		linkedList.add("Banana");
+		linkedList.add("Grapes");
+		linkedList.add("Watermelon");
+		linkedList.add("Apple");
+		linkedList.add("Avocado");
+		System.out.println("Iterating through LinkedList using Iterator interface........\n");
+
+		// getting iterator
+		Iterator<String> iterator = linkedList.iterator();
+
+		// hasNext() returns true only if object is available at next call
+		while (iterator.hasNext()) {
+
+			// next() returns obejct, we can cast it to reuqired type
+			String str = iterator.next();
+			System.out.println("Object form the LinkedList is " + str);
+		}
+	}
+}
\ No newline at end of file
diff --git a/collections/linkedlist/iterate-linkedlist-in-java/LinkedListWhileLoop.java b/collections/linkedlist/iterate-linkedlist-in-java/LinkedListWhileLoop.java
new file mode 100644
index 0000000..3293863
--- /dev/null
+++ b/collections/linkedlist/iterate-linkedlist-in-java/LinkedListWhileLoop.java
@@ -0,0 +1,44 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * A java program to iterate over linkedList
+ * using the while loop.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LinkedListWhileLoop {
+
+	public static void main(String[] args) {
+
+		List<String> linkedList = new LinkedList<String>();
+
+		linkedList.add("Mango");
+		linkedList.add("Banana");
+		linkedList.add("Grapes");
+		linkedList.add("Watermelon");
+		linkedList.add("Apple");
+		linkedList.add("Avocado");
+
+		System.out.println("Iterating through LinkedList using the while loop!\n");
+		
+		int len = linkedList.size();
+		
+		// iterate over linkedList using while loop
+		int i =0;
+		
+		while(i<len) {
+			
+			// get String object from linkedList at index i
+			String str = linkedList.get(i);
+			
+			System.out.println("Object form the LinkedList is "+str);
+			
+			//increment index after getting the object
+			i++;
+		}
+	}
+}

From 1a5a314361b80db6e079ff159c2161e0f47a17bf Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Tue, 8 Mar 2022 17:42:43 +0530
Subject: [PATCH 28/31] Add linkedlist listiterator example

---
 .../LinkedListListIteratorExample.java        | 36 +++++++++++++++++++
 .../LinkedListListIteratorException.java      | 36 +++++++++++++++++++
 2 files changed, 72 insertions(+)
 create mode 100644 collections/linkedlist/linkedlist-listiterator/LinkedListListIteratorExample.java
 create mode 100644 collections/linkedlist/linkedlist-listiterator/LinkedListListIteratorException.java

diff --git a/collections/linkedlist/linkedlist-listiterator/LinkedListListIteratorExample.java b/collections/linkedlist/linkedlist-listiterator/LinkedListListIteratorExample.java
new file mode 100644
index 0000000..7216f99
--- /dev/null
+++ b/collections/linkedlist/linkedlist-listiterator/LinkedListListIteratorExample.java
@@ -0,0 +1,36 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+import java.util.ListIterator;
+/**
+ * An example java program about the listIterator(int index)
+ * method of the linkedList.
+ * 
+ * @author coderolls.com
+ */
+public class LinkedListListIteratorExample {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> states = new LinkedList<>();
+
+		// add state in the linkedList
+		states.add("California");
+		states.add("Texas");
+		states.add("Montana");
+		states.add("Arizona");
+		states.add("Florida");
+		states.add("Michigan");
+		states.add("New Jersey");
+		states.add("Washington");
+		states.add("Ohio");
+		
+        //given index 3, iterator start from element with index 3
+		ListIterator<String> itr = states.listIterator(3);
+		System.out.println("Iterating the list from index 3\n");
+		while(itr.hasNext()) {
+			String state = itr.next();
+			System.out.println("The state :"+ state);
+		}
+	}
+}
\ No newline at end of file
diff --git a/collections/linkedlist/linkedlist-listiterator/LinkedListListIteratorException.java b/collections/linkedlist/linkedlist-listiterator/LinkedListListIteratorException.java
new file mode 100644
index 0000000..4eeb2ad
--- /dev/null
+++ b/collections/linkedlist/linkedlist-listiterator/LinkedListListIteratorException.java
@@ -0,0 +1,36 @@
+package com.gaurav.ExProject.LinkedList;
+
+import java.util.LinkedList;
+import java.util.ListIterator;
+/**
+ * An example java program about the listIterator()
+ * method of the linkedList.
+ * 
+ * @author coderolls.com
+ */
+public class LinkedListListIteratorException {
+
+	public static void main(String[] args) {
+		
+		LinkedList<String> states = new LinkedList<>();
+
+		// add state in the linkedList
+		states.add("California");
+		states.add("Texas");
+		states.add("Montana");
+		states.add("Arizona");
+		states.add("Florida");
+		states.add("Michigan");
+		states.add("New Jersey");
+		states.add("Washington");
+		states.add("Ohio");
+		
+        //given index 120, it will  throw IndexOutOfBoundsException
+		ListIterator<String> itr = states.listIterator(120);
+		
+		while(itr.hasNext()) {
+			String state = itr.next();
+			System.out.println("The state :"+ state);
+		}
+	}
+}
\ No newline at end of file

From f094820f2b13e82c60f5e52783e4befe675b9fd2 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Sat, 8 Oct 2022 17:04:07 +0530
Subject: [PATCH 29/31] Add largest element in an array examples

---
 README.md                                     |  2 +-
 .../LargestElementInArray.java                | 32 +++++++++++++++++++
 .../LargestElementInArrayUsingArrays.java     | 28 ++++++++++++++++
 .../LargestElementInArrayUsingStream.java     | 26 +++++++++++++++
 4 files changed, 87 insertions(+), 1 deletion(-)
 create mode 100644 java-programs/largest-element-in-an-array/LargestElementInArray.java
 create mode 100644 java-programs/largest-element-in-an-array/LargestElementInArrayUsingArrays.java
 create mode 100644 java-programs/largest-element-in-an-array/LargestElementInArrayUsingStream.java

diff --git a/README.md b/README.md
index 77eb236..1079472 100644
--- a/README.md
+++ b/README.md
@@ -1 +1 @@
-# Visit coderolls.com
+# Visit [coderolls.com](https://coderolls.com)
diff --git a/java-programs/largest-element-in-an-array/LargestElementInArray.java b/java-programs/largest-element-in-an-array/LargestElementInArray.java
new file mode 100644
index 0000000..a4bb4d9
--- /dev/null
+++ b/java-programs/largest-element-in-an-array/LargestElementInArray.java
@@ -0,0 +1,32 @@
+package com.coderolls.JavaPrograms;
+/**
+ * A Java program to find the largest number in an array 
+ * using for loop iteration.
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LargestElementInArray {
+
+	public static void main(String[] args) {
+		int[] arr = {2, 5, 9, 8, 11};
+		
+		int largestElement = getLargest(arr);
+		System.out.println("Largest element in an array 'arr' is :"+ largestElement);
+
+	}
+
+	private static int getLargest(int[] arr) {
+		int n = arr.length;
+		int largest = arr[0];
+		
+		for(int i=0; i<n; i++) {
+			// if number at  index i is bigger than the current largest number,
+			// copy it to 'largest' int variable
+			if(arr[i]>arr[0]) {
+				largest = arr[i];
+			}
+		}
+		return largest;
+	}
+}
diff --git a/java-programs/largest-element-in-an-array/LargestElementInArrayUsingArrays.java b/java-programs/largest-element-in-an-array/LargestElementInArrayUsingArrays.java
new file mode 100644
index 0000000..11be28b
--- /dev/null
+++ b/java-programs/largest-element-in-an-array/LargestElementInArrayUsingArrays.java
@@ -0,0 +1,28 @@
+package com.coderolls.JavaPrograms;
+
+import java.util.Arrays;
+
+/**
+ * A Java program to find the largest number in an array 
+ * using Arrays.sort().
+ * 
+ * Arrays.sort() sort the array in natural sorting order
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LargestElementInArrayUsingArrays {
+
+	public static void main(String[] args) {
+		int[] arr = {2, 5, 9, 8, 11};
+		
+		int largestElement = getLargest(arr);
+		System.out.println("Largest element in an array 'arr' using Array.sort() is :"+ largestElement);
+
+	}
+
+	private static int getLargest(int[] arr) {
+		Arrays.sort(arr);
+		return arr[arr.length-1];
+	}
+}
diff --git a/java-programs/largest-element-in-an-array/LargestElementInArrayUsingStream.java b/java-programs/largest-element-in-an-array/LargestElementInArrayUsingStream.java
new file mode 100644
index 0000000..eb6299a
--- /dev/null
+++ b/java-programs/largest-element-in-an-array/LargestElementInArrayUsingStream.java
@@ -0,0 +1,26 @@
+package com.coderolls.JavaPrograms;
+
+import java.util.Arrays;
+/**
+ * A Java program to find the largest number in an array 
+ * using Java 8 Streams API.
+ * 
+ * max() returns the maximum element of this stream
+ * 
+ * @author coderolls.com
+ *
+ */
+public class LargestElementInArrayUsingStream {
+
+	public static void main(String[] args) {
+		int[] arr = {2, 5, 9, 8, 11};
+		
+		int largestElement = getLargest(arr);
+		System.out.println("Largest element in an array 'arr' using Java 8 Streams API is :"+ largestElement);
+	}
+
+	private static int getLargest(int[] arr) {
+		int largest = Arrays.stream(arr).max().getAsInt();
+		return largest;
+	}
+}

From cda18d7544c5949baa98a1ab6854d5794149b686 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Sat, 8 Oct 2022 19:00:21 +0530
Subject: [PATCH 30/31] Add examples for second laregst element in an array

---
 .../SecondLargestElementInArray.java          | 40 +++++++++++++++++++
 ...econdLargestElementInArrayUsingArrays.java | 25 ++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 java-programs/second-largest-element-in-an-array/SecondLargestElementInArray.java
 create mode 100644 java-programs/second-largest-element-in-an-array/SecondLargestElementInArrayUsingArrays.java

diff --git a/java-programs/second-largest-element-in-an-array/SecondLargestElementInArray.java b/java-programs/second-largest-element-in-an-array/SecondLargestElementInArray.java
new file mode 100644
index 0000000..70b0b97
--- /dev/null
+++ b/java-programs/second-largest-element-in-an-array/SecondLargestElementInArray.java
@@ -0,0 +1,40 @@
+package com.coderolls.JavaPrograms.second_largest;
+/**
+ * A Java program to find the second largest number in an array 
+ * by iterating over an array using for loop.
+ * 
+ * @author coderolls.com
+ */
+public class SecondLargestElementInArray {
+
+	public static void main(String[] args) {
+		int[] arr = {2, 5, 9, 8, 11, 18, 13};
+		
+		int secondLargest = getSecondLargest(arr);
+		System.out.println("The second largest element in an array 'arr' is :"+ secondLargest);
+	}
+
+	private static int getSecondLargest(int[] arr) {
+		int n =arr.length;
+		int largest =arr[0];
+		int secondLargest = -1;
+		
+		for(int i=0; i<n; i++) {
+			if(arr[i]>largest) {
+				//if you found the new largest,
+				//copy current largest to second largest and
+				//copy current element arr[i] to largest
+				secondLargest = largest;
+				largest = arr[i];
+			}else if(arr[i]!=largest) {
+				// if the current element arr[i] is not the largest and 
+				// still larger than the current secondLargest
+				// then copy it to secondLargest
+				if(arr[i]>secondLargest) {
+					secondLargest = arr[i];
+				}
+			}
+		}
+		return secondLargest;
+	}
+}
diff --git a/java-programs/second-largest-element-in-an-array/SecondLargestElementInArrayUsingArrays.java b/java-programs/second-largest-element-in-an-array/SecondLargestElementInArrayUsingArrays.java
new file mode 100644
index 0000000..dcd0803
--- /dev/null
+++ b/java-programs/second-largest-element-in-an-array/SecondLargestElementInArrayUsingArrays.java
@@ -0,0 +1,25 @@
+package com.coderolls.JavaPrograms.second_largest;
+
+import java.util.Arrays;
+
+/**
+ * A Java program to find the second largest number in an array 
+ * using Arrays.sort() method.
+ * 
+ * @author coderolls.com
+ */
+public class SecondLargestElementInArrayUsingArrays {
+
+	public static void main(String[] args) {
+		int[] arr = {2, 5, 9, 8, 11, 18, 13};
+		
+		int secondLargest = getSecondLargest(arr);
+		System.out.println("The second largest element in an array 'arr' is using Arrays.sort() :"+ secondLargest);
+	}
+
+	private static int getSecondLargest(int[] arr) {
+		Arrays.sort(arr);
+		// return second largest, so length-2
+		return arr[arr.length-2];
+	}
+}

From 707c930a55746aca155f5632e1f5a9bf327776d5 Mon Sep 17 00:00:00 2001
From: gauravkukade <gkukade54@gmail.com>
Date: Sat, 8 Oct 2022 19:14:47 +0530
Subject: [PATCH 31/31] Update sysout line in examples

---
 .../LargestElementInArrayUsingArrays.java                     | 4 ++--
 .../LargestElementInArrayUsingStream.java                     | 3 ++-
 .../SecondLargestElementInArray.java                          | 3 ++-
 .../SecondLargestElementInArrayUsingArrays.java               | 3 ++-
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/java-programs/largest-element-in-an-array/LargestElementInArrayUsingArrays.java b/java-programs/largest-element-in-an-array/LargestElementInArrayUsingArrays.java
index 11be28b..d061699 100644
--- a/java-programs/largest-element-in-an-array/LargestElementInArrayUsingArrays.java
+++ b/java-programs/largest-element-in-an-array/LargestElementInArrayUsingArrays.java
@@ -17,8 +17,8 @@ public static void main(String[] args) {
 		int[] arr = {2, 5, 9, 8, 11};
 		
 		int largestElement = getLargest(arr);
-		System.out.println("Largest element in an array 'arr' using Array.sort() is :"+ largestElement);
-
+		System.out.println("Largest element in an array 'arr' "
+				+ "using Array.sort() is :"+ largestElement);
 	}
 
 	private static int getLargest(int[] arr) {
diff --git a/java-programs/largest-element-in-an-array/LargestElementInArrayUsingStream.java b/java-programs/largest-element-in-an-array/LargestElementInArrayUsingStream.java
index eb6299a..311ee0d 100644
--- a/java-programs/largest-element-in-an-array/LargestElementInArrayUsingStream.java
+++ b/java-programs/largest-element-in-an-array/LargestElementInArrayUsingStream.java
@@ -16,7 +16,8 @@ public static void main(String[] args) {
 		int[] arr = {2, 5, 9, 8, 11};
 		
 		int largestElement = getLargest(arr);
-		System.out.println("Largest element in an array 'arr' using Java 8 Streams API is :"+ largestElement);
+		System.out.println("Largest element in an array 'arr'"
+				+ "using Java 8 Streams API is :"+ largestElement);
 	}
 
 	private static int getLargest(int[] arr) {
diff --git a/java-programs/second-largest-element-in-an-array/SecondLargestElementInArray.java b/java-programs/second-largest-element-in-an-array/SecondLargestElementInArray.java
index 70b0b97..170298a 100644
--- a/java-programs/second-largest-element-in-an-array/SecondLargestElementInArray.java
+++ b/java-programs/second-largest-element-in-an-array/SecondLargestElementInArray.java
@@ -11,7 +11,8 @@ public static void main(String[] args) {
 		int[] arr = {2, 5, 9, 8, 11, 18, 13};
 		
 		int secondLargest = getSecondLargest(arr);
-		System.out.println("The second largest element in an array 'arr' is :"+ secondLargest);
+		System.out.println("The second largest element in "
+				+ "an array 'arr'is :"+ secondLargest);
 	}
 
 	private static int getSecondLargest(int[] arr) {
diff --git a/java-programs/second-largest-element-in-an-array/SecondLargestElementInArrayUsingArrays.java b/java-programs/second-largest-element-in-an-array/SecondLargestElementInArrayUsingArrays.java
index dcd0803..5e3aa18 100644
--- a/java-programs/second-largest-element-in-an-array/SecondLargestElementInArrayUsingArrays.java
+++ b/java-programs/second-largest-element-in-an-array/SecondLargestElementInArrayUsingArrays.java
@@ -14,7 +14,8 @@ public static void main(String[] args) {
 		int[] arr = {2, 5, 9, 8, 11, 18, 13};
 		
 		int secondLargest = getSecondLargest(arr);
-		System.out.println("The second largest element in an array 'arr' is using Arrays.sort() :"+ secondLargest);
+		System.out.println("The second largest element in"
+				+ "an array 'arr' is using Arrays.sort() :"+ secondLargest);
 	}
 
 	private static int getSecondLargest(int[] arr) {