1、例子：
<html>
<head>
<script type="text/javascript" src="/jquery/jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("button").click(function(){
$("li").each(function(){
alert($(this).text())
});
});
});
</script>
</head>
<body>
<button>輸出每個列表項的值</button>//點擊此button的文本值會彈出帶有Coffee文本值的、再點擊彈出Milk、再點擊彈出Soda
<ul>
<li>Coffee</li>
<li>Milk</li>
<li>Soda</li>
</ul>
</body>
</html>