how to calculate BMI using JpotionPane , Scanner and simple calculation

task 1 practice 1

package com.company;
//The first thing to do is to reference the library we want to use:
import javax.swing.JOptionPane;
//import java.io.InputStream;
import java.util.Scanner;

public class Main {

    /*Problem 1 from Task 1
Write a program which asks the user, by means of an object of type Scanner, to enter
his/her height (in meters, as double), then the weight (in kilograms, also as a double).
Then the program displays in a message box (JOptionPane.showMessageDialog)
his/her BMI coecient (body mass index ) dened as the weight in kilograms divided
by the square of height in meters  this number should come out close to 20.
*/

    public static void main(String[] args) {
         // write your code here
         // create a JOption 
        JOptionPane jp = new JOptionPane();
         //show a joptionpane dialog using showMessageDialog
        String message = "Please enter your weight in KG";
        JOptionPane.showMessageDialog(null, message);
        Scanner sc = new Scanner(System.in);
        double kg =sc.nextDouble();
         //just reads the next double
        String message2 = "Please enter your height in METER";
        JOptionPane.showMessageDialog(null, message2);
        double meter = sc.nextDouble();
         //just reads the next double
         //The formula is BMI = kg/m2 where kg is a person's weight in kilograms and m2 is their height in metres squared.
        double bmi = kg/(meter*meter);
        System.out.println(bmi);
        String message3 = "your BMI is " +bmi ;
        JOptionPane.showMessageDialog(null,message3);
    }
}