<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title> new document </title> <meta name="generator" content="editplus" /> <meta name="author" content="" /> <meta name="keywords" content="" /> <meta name="description" content="" /> </head> <body> <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8" /> <title></title> <link type="text/css" href="../../themes/base/jquery.ui.all.css" rel="stylesheet" /> <script type="text/javascript" src="../../jquery-1.4.2.js"></script> <script type="text/javascript" src="../../external/jquery.bgiframe-2.1.1.js"></script> <script type="text/javascript" src="../../ui/jquery.ui.core.js"></script> <script type="text/javascript" src="../../ui/jquery.ui.widget.js"></script> <script type="text/javascript" src="../../ui/jquery.ui.mouse.js"></script> <script type="text/javascript" src="../../ui/jquery.ui.draggable.js"></script> <script type="text/javascript" src="../../ui/jquery.ui.position.js"></script> <script type="text/javascript" src="../../ui/jquery.ui.resizable.js"></script> <script type="text/javascript" src="../../ui/jquery.ui.dialog.js"></script> <link type="text/css" href="../demos.css" rel="stylesheet" /> <script type="text/javascript"> $(function() { //初始测试数据 var init=function(){ $("#con1").add("#con3").data("key","10001"); }; init(); var select="mytest"; var name="key"; //定义一个新选择器 $.expr[ ":" ][ select ] = function( elem ) { return !!$.data( elem, name ); }; //使用 $("div:mytest").each(function(){ alert(this.id);//结果:con1 con3 }) }); </script> </head> <body> <div id="con1"></div> <div id="con2"></div> <div id="con3"></div> </body> </html> </body> </html>
原文：http://www.cnblogs.com/wzq806341010/p/3990807.html