[charliekim]

i am setting up a program that inputs 2 user data through input dialog boxes from JOptionPane. i am using a sentinel value control that indicates when the user enters in a sentinel value set to -1, it will calculate the data inputted. this is what it looks like so far..

import java.text.DecimalFormat;
import javax.swing.JOptionPane;

//beginning class

public class Gas {

//beginning method

public static void main(String args[])

{

//declaring variables

int miles, gallons, totalmiles, totalgallons, counter;

double averagemiles, totalaverage;

String usermiles, gallonmiles, result;

//initialization

totalmiles = 0;
totalgallons = 0;
counter = 0;
averagemiles=0;
totalaverage=0;

//obtaining user inputs

usermiles = JOptionPane.showInputDialog("Enter Miles Driven or -1 to quit");

gallonmiles = JOptionPane.showInputDialog("Enter Gallons Used");

//parseing from string to integers

miles = Integer.parseInt(usermiles);

gallons = Integer.parseInt(gallonmiles);

//loop until sentinel value read from user

while (miles != -1){

//getting next user input

usermiles = JOptionPane.showInputDialog("Enter Miles Driven or -1 to quit");

gallonmiles = JOptionPane.showInputDialog("Enter Gallons Used");

miles = Integer.parseInt(usermiles); //parseing from string to integers

gallons = Integer.parseInt(gallonmiles);

totalmiles = totalmiles + miles;

totalgallons = totalgallons + gallons;

counter = counter + 1;

//end while

}

//termination phase

DecimalFormat twoDigits = new DecimalFormat("0.00");

if (counter != 0){

// calculate the averages

averagemiles = (double)miles / (double)gallons;

totalaverage = totalmiles / totalgallons;

}

//diplaying result

result = ("Average Miles/Gallon : " + averagemiles
+ "\nTotal Miles/Gallon : " + totalaverage);

JOptionPane.showMessageDialog(null, result, "Mileage", JOptionPane.INFORMATION_MESSAGE);

//terminate program

System.exit(0);

//ending method main

}

//ending class


}


for some reason, when i enter -1 to stop the second while loop, it still asks for the gallons used input box. it should by pass the whole while loop when the user enters sentinel value -1.

anyone have any ideas..