原生js的getElementsByClass

function getByClass(oParent, sClass)
{
        var aEle=oParent.getElementsByTagName('*');
        var aResult=[];
        var re=new RegExp('\\b'+sClass+'\\b', 'i');
        var i=0;
        
        for(i=0;i<aEle.length;i++)
        {
                if(re.test(aEle[i].className))
                {
                        aResult.push(aEle[i]);
                }
        }
        
        return aResult;
}

摘自：http://www.w3cfuns.com/article-5595946-1-1.html