<<<操作符需PHP5.3以上版本才能支持，下面程序在wamp环境下测试完成。
<?php
// Set the content type to be XML, so that the browser will recognise it as XML.
header( "content-type: application/xml; charset=GBK" ); 显示$xml对象时此语句要注释掉
$string = <<<XML
<?xml version='1.0' encoding='GBK'?> 此行要顶格写
<root>
<title>Forty What?</title>
<from>Joe</from>
<to>Jane</to>
<body>I know that's the answer -- but what's the question?</body>
</root>
XML;
echo $string; --显示输出受header语句有影响。
//var_dump($string);
$xml = simplexml_load_string($string);
//var_dump($xml); --如header语句保留，对象结果无法显示
?>
结果输出(echo 显示)
This XML file does not appear to have any style information associated with it. The document tree is shown below.
string
'<?xml version='1.0' encoding='GBK'?>
<root>
<title>Forty What?</title>
<from>Joe</from>
<to>Jane</to>
<body> I know that's the answer -- but what's the question? </body>
</root> ' (length=243)
Joe Jane I know that's the answer -- but what's the question?
var_dump($xml) 结果显示
object(SimpleXMLElement)[1]
public 'title' =>
string
'Forty What?' (length=11)
public 'from' =>
string
'Joe' (length=3)
public 'to' =>
string
'Jane' (length=4)
public 'body' =>
string
' I know that's the answer -- but what's the question? ' (length=58)