Added Prime Number Checker Program

Author: iamarav

Basic-Java/PrimeNumberChecker.java

@@ -0,0 +1,47 @@
+import java.util.Scanner;
+
+public class PrimeNumberChecker {
+
+	public static void main(String[] args) {
+		
+		long number,i;
+		boolean flag = false;
+		
+		System.out.println("A Program to check if the entered number is a Prime Number or not.\n---");
+		Scanner sm = new Scanner(System.in);
+		
+		System.out.print("Enter the Natural Number: ");
+		number = sm.nextInt();
+		
+		if (number==1) {
+			System.out.println("1 is not a Prime Number."
+					+ "\n---\nExplanation: "
+					+ "A natural number (i.e. 1, 2, 3, 4, 5, 6, etc.) is called a prime number\n(or a prime) if it has exactly two positive factors, 1 and the number itself.\n1 has only one positive factor i.e. no. 1 only. Hence 1 is neither prime nor composite.");
+			System.exit(0);
+			}
+		if (number<1) {
+			System.out.println("Error: Input is negative or zero.\nTry Again!\n---");
+			main(null);
+		}
+		
+		
+		for (i=2; i<number/2; i++) {
+			if(number%i==0) {
+				System.out.println(number+" is not a Prime Number. It is divisible by: "+i);
+				flag=true;
+				break;
+			}
+			if(flag) {
+				break;
+			}
+		}
+		if (flag==false) {
+			System.out.println(number+" is a Prime Number.");
+		}
+		
+		sm.close();
+		System.out.println("---\nThe Program has ended.");
+		System.exit(0);
+	}
+
+}

README.md

@@ -11,16 +11,17 @@ ___
 
 ### List of Basic Programs:
 
-| S.No. | Title                                                        | Description                                                  | Method      |
-| ----- | :----------------------------------------------------------- | ------------------------------------------------------------ | ----------- |
-| 1     | [Hello World](/Basic-Java/HelloWorld.java)                   | A simple hello world program in java.                        | main method |
-| 2     | [Algebraic Operations](/Basic-Java/AlgebraicOperations.java) | Addition, Subtraction, Multiplication, Division Program.     | if/else     |
-| 3     | [Algebraic Operations](/Basic-Java/AlgrebraicOperationsSwitchCase.java) | Addition, Subtraction, Multiplication, Division Program.     | switch/case |
-| 4     | [Even - Odd Number Checker](/Basic-Java/EvenOdd.java)        | A Program to check if the entered number is Even or Odd.     | Modulus     |
-| 5     | [Positive Negative Number Checker](/Basic-Java/PositiveNegative.java) | A Program to check if the entered number is Positive or Negative. | if/else     |
-| 6     | [Calculate Average of numbers](/Basic-Java/CalculateAverageWithArray.java) | A Program to calculate average of numbers using Array.       | Array       |
-| 7     | [Reversing a Number](/Basic-Java/ReverseNumber.java)         | A Simple Program to reverse a number                         | String      |
-| 8     | [Binary Validation](/Basic-Java/ValidateBinary.java)         | A Program which checks if the Input String is a Binary Number or not | Modulus     |
+| S.No. | Title                                                        | Description                                                  | Method             |
+| ----- | :----------------------------------------------------------- | ------------------------------------------------------------ | ------------------ |
+| 1     | [Hello World](/Basic-Java/HelloWorld.java)                   | A simple hello world program in java.                        | main method        |
+| 2     | [Algebraic Operations](/Basic-Java/AlgebraicOperations.java) | Addition, Subtraction, Multiplication, Division Program.     | if/else            |
+| 3     | [Algebraic Operations](/Basic-Java/AlgrebraicOperationsSwitchCase.java) | Addition, Subtraction, Multiplication, Division Program.     | switch/case        |
+| 4     | [Even - Odd Number Checker](/Basic-Java/EvenOdd.java)        | A Program to check if the entered number is Even or Odd.     | Modulus            |
+| 5     | [Positive Negative Number Checker](/Basic-Java/PositiveNegative.java) | A Program to check if the entered number is Positive or Negative. | if/else            |
+| 6     | [Calculate Average of numbers](/Basic-Java/CalculateAverageWithArray.java) | A Program to calculate average of numbers using Array.       | Array              |
+| 7     | [Reversing a Number](/Basic-Java/ReverseNumber.java)         | A Simple Program to reverse a number                         | String             |
+| 8     | [Binary Validation](/Basic-Java/ValidateBinary.java)         | A Program which checks if the Input String is a Binary Number or not | Modulus            |
+| 9     | [Prime Number Checker](/Basic-Java/PrimeNumberChecker.java)  | A Program to check if the entered number is a Prime Number or not. | if/else, for loops |
 
 ### List of Other Programs: