Java For Dummies Quick Reference

ButtonGroup Class

Package: javax.swing

The ButtonGroup class creates a group in which you can add radio buttons. Of course, only one radio button in a button group can be selected at any time. Thus, selecting a radio button in a button group automatically deselects any other buttons in the group.

Constructor

Constructor	Description
ButtonGroup()	Creates an empty button group

Method

Method	Description
void add(Abstract Button button)	Adds a button to the group

You’ll usually add only radio buttons to a button group, but you can add regular buttons or check boxes, too.

Before you create a button group, you should create the buttons you will add to it. Here’s an example that creates three radio buttons named small, medium, and large:

JRadioButton small, medium, large;

Now that you have buttons, you can create a button group by calling the ButtonGroup class constructor. Then, you can add the buttons to the button group by calling the add method. For example:

ButtonGroup group1 = new ButtonGroup();

group1.add(small);

group1.add(medium);

group1.add(large);

Button groups have nothing to do with the visual appearance of the buttons on the screen. Instead, button groups simply provide a logical grouping for the buttons. To visually group the buttons together, ...