<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>DOM节点关系</title>
</head>
<body>
<p id="s"><span id="ss">b</span><a id="sss">b</a></p>
</body>
<script type="text/javascript">
var s=document.getElementById('s');
var ss=document.getElementById('ss');
var sss=document.getElementById('sss');
var a=s.childNodes.item(0)
var aa=s.childNodes.item(1);
var b=s.parentNode;
var bb=ss.parentNode;
var bbb=sss.parentNode;
var c=ss.previousSibling;
var cc=ss.nextSibling;
var d=ss.ownerDocument;//该属性指向表示整个文档的文档节点
console.log(a);
console.log(aa);
console.log(b);
console.log(bb);
console.log(bbb);
console.log(c);
console.log(cc);
console.log(d);
</script>
</html>