<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<body>
<a id=‘qwe‘ class=‘asd‘ href=‘http://222sdfad.com‘></a>
<script>
function getClass(tagName, classStr) { //EG: alert(getClass(‘*‘,‘asd‘)[0]); alert(getClass(‘a‘,‘asd‘)[0]);
if (document.getElementsByClassName) {
return document.getElementsByClassName(classStr)
} else {
var nodes = document.getElementsByTagName(tagName),
ret = []
for (var i = 0; i < nodes.length; i++) {
if (hasClass(nodes[i], classStr)) {
ret.push(nodes[i])
}
}
return ret;
}
function hasClass(tagStr, classStr) {
var arr = tagStr.className.split(/\s+/);
for (var i = 0; i < arr.length; i++) {
if (arr[i] == classStr) {
return true;
}
}
return false;
}
}
***************************
function getId(id) { //EG: alert(getId(‘qwe‘));
return document.getElementById(id);
}
***************************
function getTag(tag, obj) { //EG: alert(getTag(‘a‘,‘mrt‘)[0]);
return ( obj == ‘‘ ? document: getId(obj)).getElementsByTagName(tag);
}
***************************
function getStyle(obj, attr) { //EG: alert(getStyle(getId(‘qwe‘),‘margin-left‘));
if (obj.currentStyle) {
return obj.currentStyle[attr];
} else {
return getComputedStyle(obj, false)[attr];
}
}
/*
author:MRT
获取属性值
两种方法 $("a").attr("href"); DOM.getAttribute(‘href‘)
*/
</script>
</body>
</html>
JS获取（id、class、tag、style、attr）兼容所有
原文：http://www.cnblogs.com/mrt-yyy/p/4449958.html