<!DOCTYPE HTML>
<html>
<head>
<title> jqueryajax教程网 </title>
<meta name="Generator" content="EditPlus">
<meta name="Author" content="">
<meta name="Keywords" content="">
<meta name="Description" content="">
</head>
<body>
<p id="parent">
<span>span1</span>
<span>span2</span>
<p>p1</p>
<input type="text" value="1" name="name" />
<input type="text" value="2" name="passwd" />
</p>
<script>
(function (win, undefined) {
var parent = document.getElementById('parent'), //根据ID获取对象
children = parent.children,//获取指定对象下的所有dom
tagSpan = parent.getElementsByTagName('span'),//获取指定对象下的所有span
p = parent.getElementsByTagName('p'),//获取指定对象下的所有p
input = parent.getElementsByTagName('input');//获取指定对象下的所有input
console.log(tagSpan.length);
console.log(p.length);
console.log(input.length);
console.log(children.length);
}(this));
</script>
</body>
</html>