返回值:jQuerytoggleClass(className)

Add or remove one or more classes from each element in the set of matched elements, depending on either the class's presence or the value of the switch argument.

This method takes one or more class names as its parameter. In the first version, if an element in the matched set of elements already has the class, then it is removed; if an element does not have the class, then it is added. For example, we can apply .toggleClass() to a simple <div>: 

<div class="tumble">Some text.</div>

The first time we apply $('div.tumble').toggleClass('bounce'), we get the following: 

<div class="tumble bounce">Some text.</div>

The second time we apply $('div.tumble').toggleClass('bounce'), the <div> class is returned to the single tumble value: 

<div class="tumble">Some text.</div>

Applying .toggleClass('bounce spin') to the same <div> alternates between <div class="tumble bounce spin"> and <div class="tumble">.

The second version of .toggleClass() uses the second parameter for determining whether the class should be added or removed. If this parameter's value is true, then the class is added; if false, the class is removed. In essence, the statement: 

$('#foo').toggleClass(className, addOrRemove);

is equivalent to:

if (addOrRemove) {
    $('#foo').addClass(className);
  }
  else {
    $('#foo').removeClass(className);
  }

As of jQuery 1.4, the .toggleClass() method allows us to indicate the class name to be toggled by passing in a function. 

$('div.foo').toggleClass(function() {
  if ($(this).parent().is('.bar')) {
    return 'happy';
  } else {
    return 'sad';
  }
});

This example will toggle the happy class for <div class="foo"> elements if their parent element has a class of bar; otherwise, it will toggle the sad class.

示例:

Toggle the class 'highlight' when a paragraph is clicked.

<!DOCTYPE html>
<html>
<head>
<style>

  p { margin: 4px; font-size:16px; font-weight:bolder; 
      cursor:pointer; }
  .blue { color:blue; }
  .highlight { background:yellow; }
  </style>
<script src="jquery.min.js"></script>
</head>
<body>

<p class="blue">Click to toggle</p>
  <p class="blue highlight">highlight</p>
  <p class="blue">on these</p>
  <p class="blue">paragraphs</p>

<script>


    $("p").click(function () {
      $(this).toggleClass("highlight");
    });


</script>
</body>
</html>
演示:

示例:

Add the "highlight" class to the clicked paragraph on every third click of that paragraph, remove it every first and second click. 

<!DOCTYPE html>
<html>
<head>
<style>
  p { margin: 4px; font-size:16px; font-weight:bolder; 
      cursor:pointer; }
  .blue { color:blue; }
  .highlight { background:red; }
  </style>
<script src="jquery.min.js"></script>
</head>
<body>

<p class="blue">Click to toggle (<span>clicks: 0</span>)</p>
  <p class="blue highlight">highlight (<span>clicks: 0</span>)</p>
  <p class="blue">on these (<span>clicks: 0</span>)</p>

  <p class="blue">paragraphs (<span>clicks: 0</span>)</p>

<script>


var count = 0;
$("p").each(function() {
  var $thisParagraph = $(this);
  var count = 0;
  $thisParagraph.click(function() {
    count++;
    $thisParagraph.find("span").text('clicks: ' + count);
    $thisParagraph.toggleClass("highlight", count % 3 == 0);
  });
});



</script>
</body>
</html>
演示: