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CHAPTER 3

checked or unchecked states of check boxes and radio buttons, and will return the
value of check boxes or radio buttons as defined by their

value

attribute, regard-

less of whether they are checked or not.

For radio buttons, the power of jQuery selectors combined with the

val()

method saves the day. Consider a form with a radio group (a set of radio buttons
with the same name) named

radioGroup

and the following expression:

$('[name=radioGroup]:checked').val()

This expression returns the value of the single checked radio button (or

unde-

fined

if none is checked). That's a lot easier than looping through the buttons

looking for the checked element, isn't it? Since

val()

only considers the first ele-

ment in a wrapped set, it's not as useful for check box groups where more than
one control might be checked.

If we want to obtain the values with which the controls would be submitted

through a form submission, we'll be much better off using the

serialize()

com-

mand (which we'll see in chapter 8) or the official Form Plugin.

Another common operation we'll perform is to set the value of a form ele-

ment. The

val()

command is also used for this purpose by supplying a value. Its

syntax is as follows:

Like the

get

variant of this command, this function has its limitations. It can't set

multiple values into a multiselect list, for example. This is the reason that much
more robust functionality is available in the Form Plugin. In addition to lifting
the limitations mentioned so far, it's capable of such operations as retrieving an
array of values for check box groups, serializing the elements in the wrapped set,
clearing fields, and even converting a

DOM

form into a format suitable for use

with Ajax.

Command syntax: val

Sets the passed value as the value of all matched form elements

Parameters

value

(String) A string that's set as the value property of each form element in the
wrapped set

Returns
The wrapped set