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JavaScript: The Definitive Guide, Fourth Edition
book

JavaScript: The Definitive Guide, Fourth Edition

by David Flanagan
November 2001
Intermediate to advanced content levelIntermediate to advanced
936 pages
68h 43m
English
O'Reilly Media, Inc.
Content preview from JavaScript: The Definitive Guide, Fourth Edition

Name

Radio — a graphical radio button

Availability

JavaScript 1.0; enhanced in JavaScript 1.1

Inherits from/Overrides

Inherits from Input, HTMLElement

Synopsis

The Radio button element is usually used in groups of mutually exclusive options that have the same name. To reference one Radio element within a group, use this syntax:

                  form.radio_name[j]
form.radio_name.length 

Properties

Radio inherits properties from Input and HTMLElement and defines or overrides the following:

checked

A read/write boolean that is true if the radio button is checked or false otherwise. If you set checked to true, the radio button is selected, and the previously selected button is deselected. Note, however, that setting the checked property of a radio button to false has no effect, because at least one button must always be selected; you cannot deselect a radio button except by selecting some other button. Note also that setting the checked property does not cause the Radio button element’s onclick event handler to be invoked. If you want to invoke that event handler, you must do so explicitly.

defaultChecked

A boolean property that is true if the radio button is initially selected, but only if the checked attribute appears in the button’s HTML <input> tag. If this tag does not appear, the radio button is initially deselected, and defaultChecked is false.

value

A read/write string that specifies the text passed to the web server if the radio button is checked when the form is submitted. The initial value ...

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Publisher Resources

ISBN: 0596000480Supplemental ContentCatalog PageErrata