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A check box provides a way to make a single on-off choice; it consists of a tiny box and a label. The box typically holds a little ‘x’ (or some other indication that it is set) or is empty depending on whether that item was selected.

You’ll normally create a Checkbox using a constructor that takes the label as an argument. You can get and set the state, and also get and set the label if you want to read or change it after the Checkbox has been created. Note that the capitalization of Checkbox is inconsistent with the other controls, which could catch you by surprise since you might expect it to be "CheckBox." Whenever a Checkbox is set or cleared an event occurs, which you can capture the same way you do a button.

The concept of a radio button in GUI programming comes from pre-electronic car radios with mechanical buttons: when you push one in, any other button that was pressed pops out. Thus it allows you to force a single choice among many.

The AWT does not have a separate class to represent the radio button; instead it reuses the Checkbox. However, to put the Checkbox in a radio button group (and to change its shape so it’s visually different from an ordinary Checkbox) you must use a special constructor that takes a CheckboxGroup object as an argument. (You can also call setCheckboxGroup( ) after the Checkbox has been created.)

A CheckboxGroup has no constructor argument; its sole reason for existence is to collect some Checkboxes into a group of radio buttons. One of the Checkbox objects must have its state set to true before you try to display the group of radio buttons; otherwise you’ll get an exception at run time. If you try to set more than one radio button to true then only the final one set will be true.

Here is an example using Checkbox and CheckboxGroup