<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
</head>
<body>
<ul id="con">
<li id="lesson1">javascript
<ul>
<li id="tcon"> 基础语法</li>
<li>流程控制语句</li>
<li>函数</li>
<li>事件</li>
<li>DOM</li>
</ul>
</li>
<li id="lesson2">das</li>
<li id="lesson3">dadf</li>
<li id="lesson4">HTML/CSS
<ul>
<li>文字</li>
<li>段落</li>
<li>表单</li>
<li>表格</li>
</ul>
</li></ul>
<script type="text/javascript">
var mylist = document.getElementById("tcon");
document.write(mylist.parentNode.parentNode.parentNode.lastChild.innerHTML);
var childs = mylist.parentNode.parentNode.parentNode.childNodes;
document.write(childs[childs.length-7].innerHTML);
for(var i=0;i<childs.length;i++){
document.write(childs[1].getAttribute("id"));//为啥这样就有输出
if(childs[i].getAttribute("id")=="lesson4"){//这样程序就不走了
document.write(childs[i].innerHTML);
}
}
</script>
</body>
</html>
因为childs[i].getAttribute("id")当i=0时，childs[0]是#text没有id这个属性，所有就不继续运行了
for(var i=0;i<childs.length;i++){
if (childs[i].nodeType == 1) {//过滤掉#text
if (childs[i].getAttribute("id") == "lesson4") {//这样程序就不走了
document.write(childs[i].innerHTML);
}
}
}