PHP registerXPathNamespace()函数讲解

<?php 
$xml=<<<XML
<book xmlns:chap="http://example.org/chapter-title"> 
<title>My Book</title> 
<chapter id="1"> 
<chap:title>Chapter 1</chap:title> 
<para>Donec velit. Nullam eget tellus...</para> 
</chapter> 
<chapter id="2"> 
<chap:title>Chapter 2</chap:title> 
<para>Lorem ipsum dolor sit amet....</para> 
</chapter> 
</book> 
XML;
$sxe=new SimpleXMLElement($xml); 
$sxe->registerXPathNamespace('c','http://example.org/chapter-title'); 
$result=$sxe->xpath('//c:title'); 
foreach ($result as $title) 
{ 
echo $title . "<br>"; 
} 
?>

registerXPathNamespace( _prefix_ , _ns_ );