php 操作xml

操作xml，即是：读取和修改xml文档的数据！ 
读取： 
①：读取某一固定结点的数据： 
if (file_exists('test.xml')) { 
    $xml = simplexml_load_file('test.xml'); 
} else { 
    exit('Failed to open test.xml.'); 
} 

<?php
$xml = simplexml_load_file("data.xml");
echo $xml->baby->class->toy[1]->name ;
?>

说明：显示<baby><class><toy>(第二个)下<name>的文本！ 
②：显示某一结点下所有子结点的数据： 

<?php
$xml = simplexml_load_file("test.xml");
foreach($xml->baby->class->toy[1]->children() as $child){
  echo $child->getName() . ": " . $child . "<br />";
}?>

说明：显示<baby><class><toy>(第二个)所有子结点的名称和数据！ 
修改 

<?php
$xml = simplexml_load_file("test.xml");
foreach($xml->baby->class->toy[1]->children() as $child){
  echo $child->getName() . ": " . $child . "<br />";
}?>