51help TIY
码：
<html> <head> <script type="text/javascript" src="../jquery/jquery.js" tppabs="http://www.51help.tk/jquery/jquery.js"></script> <script type="text/javascript"> $(document).ready(function(){ $("button").click(function(){ alert($(".hot").index($("#favorite"))); }); }); </script> </head> <body> <p>获得 id="favorite" 于 jQuery 选择器 (class="hot") 的 index：</p> <button>获得 index</button> <ul> <li>Milk</li> <li class="hot">Tea</li> <li class="hot" id="favorite">Coffee</li> </ul> </body> </html>
查看结果: