JavaScript: The Definitive Guide, Fourth Edition

Name

Select — a graphical selection list

Availability

JavaScript 1.0; enhanced in JavaScript 1.1

Inherits from/Overrides

Inherits from Input, HTMLElement

Synopsis

                  form.element_name 
                  form.elements[i]

Properties

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

length

A read-only integer that specifies the number of elements in the options[] array. The value of this property is the same as options.length.

options

An array of Option objects, each of which describes one of the options displayed within the Select element. See the Select.options[] reference page for details about this array, including techniques for modifying the options displayed by the Select object.

selectedIndex

An integer that specifies the index of the selected option within the Select object. If no option is selected, selectedIndex is -1. If more than one option is selected, selectedIndex specifies the index of the first one only.

In JavaScript 1.0, selectedIndex is a read-only property. In JavaScript 1.1, it is read/write. Setting the value of this property selects the specified option and deselects all other options, even if the Select object has the multiple attribute specified. When you’re doing list-box selection (instead of drop-down menu selection), you can deselect all options by setting selectedIndex to -1. Note that changing the selection in this way does not trigger the onchange( ) event handler.

type [ JavaScript 1.1]

A read-only string property shared ...