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JAVA APPLET

 As noted previously, check boxes and radio buttons are both created with the same class, Checkbox, but radio buttons are Checkboxes placed into a CheckboxGroup. In either case, the interesting event is ItemEvent, for which you create an ItemListener.

When dealing with a group of check boxes or radio buttons, you have a choice. You can either create a new inner class to handle the event for each different Checkbox or you can create one inner class that determines which Checkbox was clicked and register a single object of that inner class with each Checkbox object.

The following example shows both approaches:

import java.applet.Applet; import java.awt.*; import java.awt.event.*; public class checkbox extends Applet implements ItemListener { CheckboxGroup chkgroup; Checkbox chknet,chktv,radmale,radfemale; TextField txtsex; TextField txttv; TextField txtnet; public void init() { chkgroup = new CheckboxGroup(); chknet = new Checkbox("NET"); chktv = new Checkbox("TV"); radmale = new Checkbox("Male",true,chkgroup); radfemale = new Checkbox("Female",false,chkgroup); txttv = new TextField(10); txtnet = new TextField(10); txtsex = new TextField(10); add(chknet); chknet.addItemListener(this); add(txtnet); add(chktv); chktv.addItemListener(this); add(txttv); add(radmale); radmale.addItemListener(this); add(radfemale); radfemale.addItemListener(this); add(txtsex); } public void itemStateChanged(ItemEvent ie) { if(ie.getItemSelectable()==chknet) { txtnet.setText("Internet"); } if(chknet.getState()==false) { txtnet.setText(" "); } if(ie.getItemSelectable()==chktv) { txttv.setText("TV"); } if(chktv.getState()==false) { txttv.setText(" "); } if(ie.getItemSelectable()==radmale) { txtsex.setText("Male"); } if(ie.getItemSelectable()==radfemale) { txtsex.setText("Female"); } } }