在线运行代码 - 菜鸟教程

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>菜鸟教程(cainiaoplay.com)</title>
<style>.ancestors *{ 
	display: block;
	border: 2px solid lightgrey;
	color: lightgrey;
	padding: 5px;
	margin: 15px;
}
</style>
<script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
	var listItemII=document.getElementById("dom");
	$("li").closest("ul",listItemII).css({"color":"red","border":"2px solid red"});
});
</script>
</head>

<body class="ancestors">body (曾曾祖先节点)
	<div style="width:500px;">div (曾祖先节点)
		<ul id="dom">ul (第二祖先 - 第二个祖先节点) 
			<ul id="dom">ul (第一祖先 - 第一个祖先节点)
				<li>li (直接父节点)
					<span>span</span>
				</li>
			</ul>
		</ul>   
	</div>
</body>

</html>
源代码

动行结果
