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<title>Document</title>
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function getByClass(oParrent, sClass) {
var aEle = oParrent.getElementsByTagName(‘*‘);
var aResult = [];
var i = 0;
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if (aEle[i].className == sClass) {
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return aResult;
}
window.onload = function() {
var oUl = document.getElementById(‘ul1‘);
var oBox = getByClass(oUl, ‘box‘);
var i = 0;
for (i = 0; i < oBox.length; i++) {
oBox[i].style.background = "yellow";
}
// var aLi = document.getElementsByTagName(‘li‘);
// var i = 0;
// // alert(‘1‘);
// for (i = 0; i < aLi.length; i++) {
// if (aLi[i].className == ‘box‘) {
// aLi[i].style.background = "red";
// }
// }
}
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<body>
<ul id="ul1">
<li></li>
<li></li>
<li class="box"></li>
<li></li>
<li></li>
<li class="box"></li>
<li class="box"></li>
<li></li>
</ul>
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原文：http://www.cnblogs.com/Mr-W/p/6485387.html