Check boxes are used to select a boolean value. Each Checkbox has a label that should be used to tell the user what the Checkbox represents. For instance a Checkbox with the label "Anchovies" would be checked if the user wants anchovies on their pizza and unchecked if they don't.


Checkboxes are often used to select from a list of possible choices when as few selections as zero or as many as everything on the list may be made. Adding a Checkbox to an applet is simple. Just declare it, construct it and add it.

  Checkbox c = new Checkbox("Pepperoni"));

As usual these steps may be combined into the single line

add(new Checkbox("Pepperoni"));

By default check boxes are unchecked when created. If you want a Checkbox to start life checked, use the following constructor instead:

add(new Checkbox("Pepperoni", null, true));

The null is a reference to a CheckboxGroup. Passing null for this argument says that this Checkbox does not belong to a CheckboxGroup.

Every Checkbox has a boolean value, either true or false. When the Checkbox is checked that value is true. When it is unchecked that value is false. You access this value using the Checkbox's getState() and setState(boolean b) methods. For example

  private void handleCheckbox(Checkbox c) {
    if (c.getState()) price += 0.50;
    else price -= 0.50;

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Copyright 1997, 1999, 2002, 2003 Elliotte Rusty Harold
Last Modified April 8, 2003