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<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>無標題文檔</title>
</head>
<body>
<p id="intro">我的課程</p>
<ul>
<li title="JS">JavaScript</li>
<li title="JQ">JQuery</li>
<li title="">HTML/CSS</li>
<li title="JAVA">JAVA</li>
<li title="">PHP</li>
</ul>
<h1>以下為li列表title的值,當title為空時，新設置值為"WEB前端技術":</h1>
<script type="text/javascript">
var Lists=document.getElementsByTagName("li");
for (var i=0; i<Lists.length;i++)
{
//獲取現在的title的屬性
var text = Lists[i].getAttribute("title");
document.write(text +"<br>");
if(text=="")
{
//添加現在的title的新屬性
Lists[i].setAttribute("title","WEB前端技術");
document.write(Lists[i].getAttribute("title")+"<br>");
}
}
</script>
</body>
</html>