直接上代码
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>无标题文档</title>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript">
$(function(){
$("li").click(function(){
alert($(this).index());
})
});
</script>
</head>
<body>
<ul>
<li>1</li>
<li>2</li>
<li>3</li>
<li>4</li>
</ul>
</body>
</html>