运行结果： 前一个节点出不来
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>兄弟节点</title>
</head>
<body>
<ul id="u1">
<li id="a">javascript</li>
<li id="b">jquery</li>
<li id="c">html</li>
</ul>
<ul id="u2">
<li id="d">css3</li>
<li id="e">php</li>
<li id="f">java</li>
</ul>
<script type="text/javascript">
function get_nextSibling(n){
var x=n.nextSibling;
while (x&&x.nodeType!=1){
x=x.nextSibling;
}
return x;
}
function get_previousSibling(n) {
var a=n.previousSibling;
while(a&&a.nodeType!=1){
a=a.previousSibling;
}
return b;
}
var x=document.getElementsByTagName("li")[0];
document.write(x.nodeName);
document.write(" = ");
document.write(x.innerHTML);
var y=get_nextSibling(x);
if(y!=null){
document.write("<br />nextSibling: ");
document.write(y.nodeName);
document.write(" = ");
document.write(y.innerHTML+"<br /><br />");
}else{
document.write("<br>已经是最后一个节点"+"<br /><br />");
}
var a=document.getElementsByTagName("li")[2];
document.write("</br>"+a.nodeName);
document.write("=");
document.write(a.innerHTML);
var b=get_previousSibling(a);
if(b!=null){
document.write("</br>previousSibling");
document.write(b.nodeName);
document.write("=");
document.write(b.innerHTML+"</br>")
}else{
document.write("这是第一个节点")
}
</script>
</body>
</html>运行结果： 前一个节点出不来
javascript
jquery
html
css3
php
java
LI = javascript
nextSibling: LI = jquery
LI=html这是第一个节点
