PHP有没有USE这个关键词解决方案

PHP有没有USE这个关键词
我看的一些PHP的资料好像都没有USE。但是刚才看一个框架时发现里面用到了USE。

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我猜 没有吧
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这个不明白啊
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namespace foo;
use My\Full\Classname as Another;

// this is the same as use My\Full\NSname as NSname
use My\Full\NSname;

// importing a global class
use ArrayObject;

$obj = new namespace\Another; // instantiates object of class foo\Another
$obj = new Another; // instantiates object of class My\Full\Classname
NSname\subns\func(); // calls function My\Full\NSname\subns\func
$a = new ArrayObject(array(1)); // instantiates object of class ArrayObject
// without the "use ArrayObject" we would instantiate an object of class foo\ArrayObject
?>
好像是给一个类定义别名：如下

use class3 as Another;
use class3 as Another1;
use class3 as Another2;

$obj = new Another; //
$obj = new Another1; //
$obj = new Another2; //

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php 5.3+