为什么这里设置(that.className="select";)可以使用反而根据视频教程编写的( titles[that.index].className="select";),就没反应呢?
function select(id){
return typeof id==="string"?document.getElementById(id):id;
}
window.onload=function(){
var timer =null;
var titles =select("notice-tit").getElementsByTagName("li"),
divs =select("notice-con").getElementsByTagName("div");
if(titles.length!==divs.length){
return;
}
for (var i =0;i<titles.length;i++){
titles[i].index=i;
titles[i].onmouseover=function(){
var that=this;
if (timer){
clearTimeout(timer);
timer=null;
}
timer =setTimeout(function(){
for(var j=0;j<titles.length;j++){
titles[j].className="";
divs[j].style.display="none";
}
that.className="select";
/* titles[that.index].className="select";*/
divs[that.index].style.display="block";
},500);
}
}
}