Completed Task_1

MyString.java

@@ -0,0 +1,223 @@
+import java.util.*; 
+
+class StringOp{
+    String currentString = new String("");
+	StringOp(String s){
+		this.currentString=s;
+	}
+	//Function to append the String
+    public String append(String given_String) {
+		if (currentString.length()>0)       //adding spaces between words
+			currentString+=' ';
+        currentString+=given_String;
+		return currentString;
+    }
+
+	//function to count the words in the string
+    public int countWords() {
+        String temp_st = new String("");   //temporary string to store the word
+		int word_count=0;
+        for (char ch : currentString.toCharArray()) {
+            if (ch == ' ' || ch==',') {
+                if (temp_st.length() > 0) {
+                    word_count++;   //adding the word count
+                    temp_st="";   //making the string empty
+                }
+            } else {
+                temp_st+=ch;        //adding character in string
+            }
+        }
+        if (temp_st.length() > 0) 
+			word_count++;      //adding last word count
+        return word_count;
+    }
+
+	//function to reverse the string
+	public String reverseString() {
+		char[] char_array = currentString.toCharArray(); // Convert to char array
+		char[] reversed = new char[char_array.length]; // Create array for reversed characters
+
+		for (int i = char_array.length - 1, j = 0; i >= 0; i--, j++) {
+			reversed[j] = char_array[i]; 
+		}
+
+		currentString = new String(reversed);      //converted the char[] in string
+		return currentString;
+	}
+
+	//function to replace the character in the string
+	public String replaceChar(char a,char b){
+		String temp_string=new String("");		//making temp empty string for storing the char
+		for (char ch: currentString.toCharArray()){
+			if (ch==a){
+				temp_string+=b;
+			}
+			else{
+				temp_string+=ch;
+			}
+		}
+		currentString=temp_string;
+		return currentString;
+	}
+	//function to delete the substring
+	public String stringSlice(int start,int len){
+		if (start < 0 || start+len > currentString.length() || start>currentString.length()) {   //valid checks befor slicing
+			return currentString;
+		}
+		currentString=currentString.substring(0,start)+currentString.substring(start+len);
+		return currentString;
+	}
+	//function to split string in array
+	public List<String> splitString(){
+		List<String> word_List = new ArrayList<>();
+        String st = new String("");     
+        for (char ch : currentString.toCharArray()) {
+            if (ch == ' ') {
+                if (st.length() > 0) {
+                    word_List.add(st);
+                    st="";
+                }
+            } else {
+                st+=ch;
+            }
+        }
+        if (st.length() > 0) 
+			word_List.add(st);
+		return word_List;
+	}
+	//function to check the string is pallindrome or not
+	public boolean isPalindrome() {
+		char[] st=currentString.toLowerCase().toCharArray(); // Convert to char array
+		int left=0;
+		int right=st.length-1;
+		while(left<=right){
+			if (st[left]!=st[right]){
+				return false;
+			}
+			left++;
+			right--;
+		}
+		return true;
+	}
+
+	//function to shift the char of the string
+	public String stringShift(int n){
+		if (n<0)
+			return currentString ;
+		int len = currentString.length();
+		if (len == 0) return currentString;
+		n = n % len; 
+		String s = currentString;
+		String shifted = s.substring(len - n) + s.substring(0, len - n);
+		currentString = new String(shifted);
+		return currentString;
+
+	}
+
+	//function to find the repeating char in string
+    public void maxRepeat() {
+		String temp = currentString.toLowerCase();
+        int[] freq = new int[256];         //intitalizing the frequency array 
+        for (char c : temp.toCharArray()) {
+            freq[c]++;
+        }
+
+        char maxChar = ' ';
+        int maxCount = 0;
+        for (char c : temp.toCharArray()) {
+			if (c!=' '){
+				if (freq[c] > maxCount) {
+					maxCount = freq[c];
+					maxChar = c;
+				}
+			}
+        }
+
+        System.out.println("Character with maximum occurrence: " + maxChar + " -> " + maxCount);
+    }
+
+	//function to sort the string
+	public String sortString() {
+		char[] sstring = currentString.toLowerCase().toCharArray();
+		Arrays.sort(sstring);  
+		currentString = new String(sstring);
+		return currentString;
+	}
+}
+
+class MyString{
+    public static void main(String[] args) {
+        Scanner obj = new Scanner(System.in);
+        int option = 0;
+
+        System.out.print("Enter the initial string: ");
+		StringOp str = new StringOp(obj.nextLine());
+        while (option != 11) {
+            System.out.println("\nSelect the Operation:");
+            System.out.println("1. Append the string");
+            System.out.println("2. Count the words");
+            System.out.println("3. Replace the character");
+            System.out.println("4. Check Palindrome");
+            System.out.println("5. Slicing the string");
+            System.out.println("6. Split the String");
+            System.out.println("7. Maximum Repeating Character");
+            System.out.println("8. Sort the String");
+            System.out.println("9. Shift character in string");
+            System.out.println("10. Reverse the string");
+            System.out.println("11. Exit");
+			System.out.println("currentString:"+str.currentString);
+            System.out.print("Enter your choice: ");
+            option = obj.nextInt();
+            obj.nextLine(); 
+
+            switch (option) {
+                case 1:
+                    System.out.print("Enter the string to append: ");
+                    System.out.println("Appended String: " + str.append(obj.nextLine()));
+                    break;
+                case 2:
+                    System.out.println("Word count: " + str.countWords());
+                    break;
+				case 3:
+					System.out.println("Enter the character to replace :");
+					char a=obj.next().charAt(0);
+					System.out.println("Enter the character to replace with:");
+					char b=obj.next().charAt(0);
+					System.out.println("String:"+str.replaceChar(a,b));
+					break;
+				case 4:
+					System.out.println(str.isPalindrome());
+					break;
+				case 5:
+					System.out.println("Enter the start and length (s,l) to delete:");
+					int start=obj.nextInt();
+					int len=obj.nextInt();
+					System.out.println("Sliced String:"+str.stringSlice(start,len));
+					break;
+				case 6:
+					System.out.println("String:"+str.splitString());
+					break;
+                case 7:
+                    str.maxRepeat();
+                    break;
+				case 8:
+					System.out.print("Sorted String:"+str.sortString());
+					break;
+				case 9:
+					System.out.print("Enter shift no: ");
+					int n = obj.nextInt();
+					System.out.print("String:"+str.stringShift(n));
+					break;
+                case 10:
+					System.out.print("Reverse String:"+ str.reverseString());
+                    break;
+                case 11:
+                    System.out.println("Exiting...");
+                    break;
+                default:
+                    System.out.println("Incorrect option!");
+            }
+        }
+        obj.close();
+    }
+}