闰闰的妈妈
2018-05-10 21:48
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
</head>
<body>
<p id="intro">我的课程</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>以下为li列表title的值,当title为空时,新设置值为"WEB前端技术":</h1>
<script type="text/javascript">
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前段技术");
document.write(Lists[i].getAttribute("title")+"<br>");
}
}
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>设置标签的属性值</title>
</head>
<body>
<p id="intro">我的课程</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">PHP</li>
</ul>
<h1>以下为LI列表的title值,当title为空时,新设置的值为web前端技术</h1>
<script type="text/javascript">
var x=document.getElementsByTagName("li");
for(var i=0;i<x.length;i++){
var text=x[i].getAttribute("title");
if(text==""){
x[i].setAttribute("title", "web前端技术");
}
document.write(x[i].getAttribute("title")+"<br/>");
}
</script>
</body>
</html>
25行的分号是中文的分号,应该改成英文分号输出
JavaScript进阶篇
468194 学习 · 21891 问题
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