<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"/>
<title>是否是有效的dom节点</title>
<script type="text/javascript">
//是否是节点（body有效）
function isNode(elem) {
var ts = Object.prototype.toString;
var reg = /^([object HTML).*?(Element])$/;
var str = ts.call(elem);
//IE8下body会识别成[object Object]
if (reg.test(str)
|| (elem !== undefined
&& elem !== null
&& elem.nodeName !== undefined
&& elem.nodeName !== '#text'
&& elem.nodeName !== '#document')) {
return true;
}
return false;
}
</script>
</head>
<body>
<ul>
<li>
列表节点
</li>
</ul>
<h4>单测结果输出：</h4>
<script type="text/javascript">
//简单测试框架
function test(testArr, expectArr, explain) {
var tStr;
for (var i = 0, len = testArr.length; i < len; i++) {
if(explain && explain[i]){
tStr = explain[i] + ' -> ' + expectArr[i] + ':';
}
if (isNode(testArr[i]) === expectArr[i]) {
tStr += '成功';
} else {
tStr += '失败';
}
document.write(tStr + '<br />');
}
}
// 对验证的说明
var explain;
//预期结果
var expect;
var ul = document.getElementsByTagName('ul')[0];
var childNodes = ul.childNodes;
if (childNodes.length == 3) {
expect = [false, true, false];
explain = [
'标准浏览器下childNodes获取的换行文本节点',
'标准浏览器下childNodes获取的Dom节点',
'标准浏览器下childNodes获取的换行文本节点'
];
} else {
expect = [true];
explain = ['IE下childNodes获取的Dom节点'];
}
test(childNodes, expect, explain);
document.write('------------------------<br />');
var testArr =
[
document,
window,
document.body,
undefined,
null,
true,
false,
'' ,
0,
2 / 0,
new Number(3),
'str',
new String('str'),
new String('')
];
expect =
[
false,
false,
true,
false,
false,
false,
false,
false,
false,
false,
false,
false,
false,
false
];
// 对验证的说明
explain = [
'document',
'window',
'document.body',
'undefined',
'null',
'true',
'false',
'空字符串',
'数字0',
'NaN,如2/0',
'new Number(3)',
'str',
'new String("str")',
'new String("")'
];
test(testArr, expect, explain);
document.write('------------------------<br />');
//这种变态构造就管不了了
test([
{nodeName: 'DIV'}
], [false]);
</script>
</body>
</html>