JS封装通过className获取元素的函数示例

<div id="box">  <div class="star"></div>  <div class="star"></div>  <div class="app"></div>  <p class="star"></p>  <p class="ar"></p></div>

function getByClass(oparent,sClass){  var aEle=oparent.getElementsByTagName("*");  var aResult=[];  var i;  for(i=0;i<aEle.length;i++){    if(aEle[i].className==sClass){      aResult.push(aEle[i]);    }  }  return aResult;};window.onload=function(){  var box=document.getElementById("box");  var star=getByClass(box,"star");};