1 <?xml version="1.0 encoding="UTF-8"?>
 2 <people nation="汉族" city="火星">
 3     <xiaohua college="qinghua">
 4         <name>小华</name>
 5         <age>12</age>
 6         <sex>男</sex>
 7     </xiaohua>
 8     <xiaoming college="beida">
 9         <name>小明</name>
10         <age>15</age>
11         <sex>男</sex>
12     </xiaoming>
13     <xiaoqiang college="jiaotong">
14         <name>小强</name>
15         <age>13</age>
16         <sex>男</sex>
17     </xiaoqiang>
18 </people>    

<?php
    $dom = new DomDocument();
    $dom->load(a.xml);
    $people = $dom->getElementByTagName('people');//获取people的节点数组

    $people->item(0);//获取第一个people节点
    $people->item(0)->childNodes;//获取第一个people节点的所有子节点
    $people->item(0)->attributes;//获取第一个people节点的所有属性

    $people->item(0)->childNodes->item(0);//获取第一个people节点的第一个节点,即xiaohua节点
    $people->item(0)->attributes->item(0);//获取第一个people节点的第一个属性,即nation属性。
    $people->item(0)->childNodes->item(0)->childNodes->item(0);//获取第一个people节点的第一个节点里的name节点

    echo $people->item(0)->attributes->item(0)->nodeName;//输出字符串:nation
    echo $people->item(0)->attributes->item(0)->nodeValue//输出字符串：汉族
    echo $people->item(0)->childNodes->item(0)->childNodes->item(0)->nodeName;//输出字符串：name
　　echo $people->item(0)->childNodes->item(0)->childNodes->item(0)->nodeValue;//输出字符串：小华

　　foreach($people->item(0)->attributes as $key => $value){//遍历节点
　　　　echo $key;//第一次输出字符串：nation，第二次输出字符串：city
　　　　echo $value->nodeValue;//第一次输出字符串：汉族，第二次输出字符串：火星
　　}