Java Program to calculate and display the square of any number

import java.io.*;
import java.util.*;
public class SquareOfNumber{
    Scanner scan=new Scanner(System.in);
    double num=0;
    double square;
    public void input()throws IOException{
        System.out.println("Enter any number to find its square: ");
        num=scan.nextDouble();
    }

    public void compute(){
        square=num*num;
    }

    public void display(){
        System.out.println("Square of "+num+" is: "+square);
    }

    public static void main(String[] args)throws IOException{
        SquareOfNumber obj=new SquareOfNumber();
        obj.input();
        obj.compute();
        obj.display();
    }
}

Above program is to calculate the square of any digit entered by user. If you want to find the cube of any number, then just change the code line "square=num*num;" to "<variable_name>=num*num*num;"