<html>
<head>
<title></title>
<script type="text/javascript">
window.onload=function(){
var urlStr='https://www.baidu.com/s?pIndex='+45;
var rec=/=(.+)/.exec(urlStr)[1];
alert(rec);
}
</script>
</head>
<body>
</body>
</html>
运行后弹出的是45。
有关更多正则学习，请详见:http://www.cnblogs.com/jamesping/articles/2252675.html#undefined
