如果存在（不存在）就删除（添加）一个类。

返回值:jQuery

参数:

• class (String): CSS类名

示例:

$("p").toggleClass("selected")

HTML 代码:

<p>Hello</p><p class="selected">Hello Again</p>

结果:

[ <p class="selected">Hello</p>, <p>Hello Again</p> ]

toggleClass( class )

Adds the specified class if it is not present, removes it if it is present.

Return value: jQuery
Parameters:

• class (String): A CSS class with which to toggle the elements

Example:

 $("p").toggleClass("selected")  

 <p>Hello</p><p class="selected">Hello Again</p>  

 [ <p class="selected">Hello</p>, <p>Hello Again</p> ]