<!DOCTYPE?HTML>
<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++)
??{
??????var?text=Lists[i].getAttribute("title");
????if(text!==""){
????document.write(text?+"<br>");}
????else
????{
????Lists[i].setAttribute("title","TEST");
????document.write(Lists[i].getAttribute("title")+"<br>");
????}
??}
</script>
</body>
</html>
2015-04-10
<!DOCTYPE?HTML>
<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 lst=document.getElementsByTagName("li");
for(var i=0;i<lst.length;i++){
var txt=lst[i].getAttribute("title");
if(txt==""){
lst[i].setAttribute("title","WEB前端技術");
}else{
document.write(lst[i].getAttribute("title")+"<br />");
}
//打印一下就知道了
//document.write(lst[i].getAttribute("title")+"<br />");
}
</script>
</body>
</html>