递归遍历节点树

<!DOCTYPE HTML>
<html>
    <head>
        <title>遍历节点树</title>
        <meta charset="utf-8"/>
        <script src="js/3_2.js"></script>
    </head>
    <body>
        <span>Hello World !</span>
        <ul id="nav">
            <li>娱乐</li>
            <li>电视剧
                <ul>
                    <li>内地</li>
                    <li>韩剧</li>
                    <li>美剧</li>
                </ul>
            </li>
            <li>电影</li>
        </ul>    
    </body>
</html>

function getChildren(parent){
      console.log(parent.nodeType==3?parent.nodeValue:parent.nodeName);
   for(var i=0,len=parent.childNodes.length;i<len;i++){
      console.log(parent.childNodes[i].nodeName);
      getChildren(parent.childNodes[i])
   }
}
window.onload=function(){
   getChildren(document.body);

nodeType: 获得当前节点的类型，返回的是一个数字(专门判断不同节点类型)

ELEMENT_NODE: 1

TEXT_NODE: 3

ATTRIBUTE_NODE: 2

DOCUMENT_NODE: 9