Prime Number with different approach, 1) Find prime number withing a range 2) Prime number using math.sqrt 3)Prime number using while loop ? Selenium webdriver experienced interview qus/Java /Prime Number qus/Most asked interview qus

 //PRIME Number within a range

public class PrimeNumber {

public static void main(String[] args) {

  // TODO Auto-generated method stub

  PrimeNumber p = new PrimeNumber();

  System.out.println("====method1========");

  p.isPrime_1(10,100);

  System.out.println("===================");

public void isPrime_1(int s1, int s2) {
         int  flag = 0, i, j;

         System.out.println ("The prime numbers in between the entered limits are :");
         for(i = s1; i <= s2; i++)
         {
             for( j = 2; j < i; j++)
             {
                 if(i % j == 0)
                 {
                     flag = 0;
                     break;
                 }
                 else
                 {
                     flag = 1;
                 }
             }
             if(flag == 1)
             {
                 System.out.println(i);
             }
         }

}

//PRIME Number using math.sqrt

public class PrimeNum {

   public static void main(String[] args) 
  {
       Scanner pnc = new Scanner(System.in);
       System.out.print("Enter a number : ");
       int n = pnc.nextInt();
       if (IsPrimeNumber(n)) 
      {
           System.out.println(n + " is a prime number");
       } else 
          {
           System.out.println(n + " is not a prime number");
          }
   }

   public static boolean IsPrimeNumber(int n) {
       if (n <= 1) 
      {
           return false;
       }
       for (int i = 2; i < Math.sqrt(n); i++) 
      {
           if (n % i == 0)
          {
               return false;
           }
       }
       return true;
   }
}

//PRIME number using while loop 

 public class PrimeNumberWhileLoop {

    public static void main(String[] args) {
         Scanner pn = new Scanner(System.in);

                       System.out.print("Enter a number : ");

                       int number = pn.nextInt();
int i = 2;
        boolean flag = false;
        while(i <= number/2)
        {
            // condition for not a prime number
            if(number % i == 0)
            {
                flag = true;
                break;
            }

            ++i;
        }

        if (!flag)
            System.out.println(number + " :is a prime number.");
        else
            System.out.println(number + " :is not a prime number.");
    }
}