Java Notes
Dialog I/O: Kilometers to Miles with Method
This program is the same as Example: Dialog: Kilometers to Miles, but with one change: the conversion of kilometers to miles is done in a method.
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// File : intro-dialog/KmToMilesMethod.java
// Purpose: Convert kilometers to miles using a method. JOptionPane IO.
// Author : Michael Maus
// Date : 28 Oct 2004
import javax.swing.*;
public class KmToMilesMethod {
//================================================================= 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 = convertKmToMi(km); //Note 1
//... Output
JOptionPane.showMessageDialog(null, km + " kilometers is "
+ mi + " miles.");
}
//========================================================= convertKmToMi
public static double convertKmToMi(double kilometers) {
// Assume there are 0.621 miles in a kilometer.
double miles = kilometers * 0.621;
return miles;
}
}
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Notes
Note 1: Call a method to do the conversion. Altho this method is trivial, just a multiplication, it is good practice to separate the "model" or "logic" of the program from user interface. As programs become larger, this separation becomes essential.