# Java: Dialog I/O: Kilometers to Miles

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    // intro-dialog/KmToMiles.java - Convert kilometers to miles.
    // Use JOptionPane for input / output.
    // Michael Maus, 28 Oct 2004

    import javax.swing.*;

    public class KmToMiles {

        //================================================================= main
        public static void main(String[] args) {
            //... Local variables
            String kmStr;    // String km before conversion to double.
            double km;       // Number of kilometers.
            double mi;       // Number of miles.

            //... Input
            kmStr = JOptionPane.showInputDialog(null, "Enter kilometers.");
            km = Double.parseDouble(kmStr);

            //... Computation
            mi = km * 0.621;  // There are 0.621 miles in a kilometer.

            //... Output
            JOptionPane.showMessageDialog(null, km + " kilometers is "
                                              + mi + " miles.");

            //... Stop
            System.exit(0);  // Stop GUI program
        }
    }