Java Program to Check Whether a number is Prime or Not

In this java program, we check whether a number is prime or not. A prime number is only divisible by 1 and itself.

Java Program to Check Whether a number is Prime or Not

public class PrimeNumber

{

 public static void main(String[] args)

 {

  int n = 83;

  boolean flag = false;

  for(int i = 2; i <= n/2; ++i)

  {            

     if(n % i == 0)

     {

       flag = true;

       break;

     }

  }

  if (!flag)

      System.out.println(n + " is a prime number.");

  else

      System.out.println(n + " is not a prime number.");

 }

}

OUTPUT:

83 is a prime number.

Java Program to Check Whether a number is Prime or Not Using Scanner

import java.util.*;

public class PrimeNumber

{

 public static void main(String[] args)

 {

  Scanner s = new Scanner(System.in);

  System.out.println("Enter a number ");

  int n = s.nextInt();

  boolean flag = false;

  for(int i = 2; i <= n/2; ++i)

  {

     if(n % i == 0)

     {

       flag = true;

       break;

     }

  }

  if (!flag)

     System.out.println(n + " is a prime number.");

  else

  System.out.println(n + " is not a prime number.");

 }

}

OUTPUT:

Enter a number

97

97 is a prime number.