Find given number in perfect square or not

Write a program for a given number in perfect square or not

import java.util.Scanner;

public class perfectsquare

{

     public static void main(String[] args)

{

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

          Scanner sc=new Scanner(System.in);
          int num=sc.nextInt();

          double num1=Math.sqrt(num);

          double num2=num1;

            if(num1==num2)
               System.out.println(num + "is a perfect square");

            else
               System.out.println(num + "is not a perfect square");

           }

}


Output:

Enter a number
100


100 is a perfect square