js获取class name

function getByClass(oParent,sClass){
    var aEle=oParent.getElementsByTagName(‘*‘);
    var aResult=[];
    
    for(var i=0;i<aEle.length;i++){
        if(aEle[i].className==sClass){
            aResult.push(aEle[i]);
        }
    }
    return aResult;
}

var oDiv=document.getElementById(‘div1‘);
var oBtnPrev=getByClass(oDiv,‘prev‘);