本人肉眼凡胎，求大神解答。在线等。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<p>课程列表</p>
<ul>
<li title="第一个li">html</li>
<li title="">css</li>
<li title="第三个li">javascript</li>
<li title="">jquery</li>
<li title="第五个li">html5</li>
</ul>
<p>以下为li列表title的值,当title为空时，新设置值为"WEB前端技术":</p>
<script type="text/javascript">
//---------------------------------------------------------------------
/*var tong = document.getElementsByTagName("li");
for(var i=0;i<tong.length;i++){
var text = tong[i].getAttribute("title");
document.write(text+"<br/>");
if(text==""){
tong[i].SetAttribute("title","WEB前端技术");
document.write(tong[i].getAttribute("title")+"<br/>")
}
} */
//--------------------------------------------------------------------------
var Lists=document.getElementsByTagName("li");
for (var i=0; i<Lists.length;i++)
{
var text = Lists[i].getAttribute("title");
document.write(text +"<br>");
if(text=="")
{
Lists[i].setAttribute("title","WEB前端技术");
document.write(Lists[i].getAttribute("title")+"<br>");
}
}
</script>
</body>
</html>
