在做单元测试框架时，发现了个比较郁闷的问题：测试人员需要在类外修改类的private或protected成员变量的值，而这些变量没有抽象成public的属性，同时为了代码量的问题，也不可能修改要测试的类。怎么在类外修改类的私有变量呢？请看下面的关键代码：
类文件sellAction.php， 内容如下：
<?phpclass SellAction{ protected $cUid; private $id; public $pId; public function output(){ echo "output protected cUid :".$this->cUid; echo "<br/>"; echo "output private id :".$this->id; echo "<br/>"; echo "output public pId:".$this->pId; echo "<br/>"; }}测试文件test.php，内容如下：
<?phprequire "sellAction.php";function initReferenceAttr(& $reference, $arr){ if(!is_object($reference)) { throw new Exception('reference must be object'); } if(!is_array($arr)) { throw new Exception('arr must be array'); } $cls = get_class($reference); $reflectCls = new ReflectionClass ($cls); foreach($arr as $key => $val) { $pro = $reflectCls->getProperty($key); if($pro && ($pro->isPrivate() || $pro->isProtected())){ $pro->setAccessible(true); $pro->setValue($reference, $val); }else{ $reference->$key = $val; } } return true;}$act = new SellAction();echo "not set private protect public var";echo "<br/>";var_dump($act);$act->output();$attr = array('cUid'=>'234556', 'pId'=>'987676757', 'id'=> '782100');initReferenceAttr($act, $attr);echo "<br/>";print_r($attr);echo "<br/>";echo "<br/>";echo "set private protect public var ";echo "<br/>";var_dump($act);echo "<br/>";$act->output();在浏览器中，直接浏览test.php，内容大致如下：
not set private protect public varobject(SellAction)#1 (3) { ["cUid":protected]=> NULL ["id":"SellAction":private]=> NULL ["pId"]=> NULL } output protected cUid :output private id :output public pId:Array ( [cUid] => 234556 [pId] => 987676757 [id] => 782100 ) set private protect public var object(SellAction)#1 (3) { ["cUid":protected]=> string(6) "234556" ["id":"SellAction":private]=> string(6) "782100" ["pId"]=> string(9) "987676757" } output protected cUid :234556output private id :782100output public pId:987676757上面的demo主要是通过反射实现该功能。反射功能需要php版本>=5.3，反射的相关信息请参阅：http://php.net/manual/en/book.reflection.php