/**
 * Weight Calculator > DialogInput.java 
 *
 * Displays a table of calculated weights on Jupiter using JOptionPane for input
 * and console output.  It also illustrates DecimalFormat for output.
  * 
 * @author  Dale Reed
 */

import javax.swing.JOptionPane;     // This class is used for dialog-based I/O
import java.text.DecimalFormat;     // Used for formatting output

public class  DialogInput {
    
    public static void main(String[] args) {
            
        // variable declarations
        double earthWeight = 100.0;         // weight on the earth, declared and initialized
        double weightMultiplier = 2.628099173553719;     
                                            // factor for finding Jupiter weight given earth's
         
        // Prompt for and get the weight on earth, using a JOptionPane
        String userInput = JOptionPane.showInputDialog(null, "Enter your weight on earth:");
        // Now convert the input string into a numerical value
        earthWeight = Double.parseDouble( userInput);
        
        // display weight on Jupiter
        double jupiterWeight = earthWeight * weightMultiplier;
        System.out.print( "If on earth you weigh " + earthWeight + ", ");
        System.out.println( "then on Jupiter you weigh " + jupiterWeight );

        // Repeat output of weight on Jupiter, this time formatting the output
        // First create the decimal format object
        DecimalFormat pattern0dot00 = new DecimalFormat("0.00");
        // Now use the decimal format object in displaying the output
        System.out.print( "If on earth you weigh " + earthWeight + ", ");
        System.out.println( "then on Jupiter you weigh " + pattern0dot00.format(jupiterWeight) );
        
        System.exit(0);
      }    
}

/* Output:

If on earth you weigh 220.0, then on Jupiter you weigh 578.1818181818182
If on earth you weigh 220.0, then on Jupiter you weigh 578.18

*/