Question:
How do you change a button’s caption after it is created?

Answer:
Java’s Button class defines two methods for getting and setting a button’s caption. They are getLabel() and setLabel(). The following simple applet creates a button whose caption changes when the user presses the button:

import java.awt.*;import java.applet.*; public class ButtonLabel extends Applet {        Button b;        boolean active = false;        // define a button with some initial label        public void init() {                b = new Button(“Inactive”);                add(b);        }        // Change the caption when the user presses the button        // after it has been created         public synchronized boolean handleEvent(Event e) {                if (e.target instanceof Button) {                        if (active) {                                active = false;                                b.setLabel(“Inactive”);                        } else {                                active = true;                                b.setLabel(“Active”);                        }                        return true;                }                return false;        }         //        // Defining a main() routine allows the applet to be        // run as a standalone Java application also        //        public static void main(String argv[]) {                Frame f = new Frame(“ButtonLabel”);                  Applet a = new ButtonLabel();                a.init();                a.start();                 f.setLayout(new BorderLayout());                f.add(“Center”, a);                f.pack();                f.show();        }}