W3School TIY
编辑您的代码：
<html> <head> <script type="text/javascript" src="../jquery/jquery.js"></script> <script type="text/javascript"> $(document).ready(function(){ $("button").click(function(){ $('ul li').toggleClass(function(){ return 'listitem_' + $(this).index(); }); }); }); </script> <style type="text/css"> .listitem_1, .listitem_3 { color:red; } .listitem_0, .listitem_2 { color:blue; } </style> </head> <body> <h1 id="h1">This is a heading</h1> <ul> <li>Apple</li> <li>IBM</li> <li>Microsoft</li> <li>Google</li> </ul> <button class="btn1">添加或移除列表项的类</button> </body> </html>
查看结果: