php函数返回引用示例

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<?php   class Test {     public $userCache;       public function init()     {         for($i = 0; $i < 5; $i++)         {             $user = array(                 'name'  => "joe$i",                 'age'   => 23 + $i,             );             $this->userCache[] = $user;         }     }       public function displayArray($arr = '')     {         if( gettype($arr) !== 'array' )             $arr = $this->userCache;           foreach($arr as $k => $v)         {             echo "$k: ";             print_r($v);             echo "\n";         }     }       public function &getUser($uid)          // 函数返回引用     {         if( isset($this->userCache[$uid]) )         {             return $user = &$this->userCache[$uid];  // $user取引用(此处不能断)         }         else         {             echo "create a new user:\n";             $user = array('name'=>'xxy', 'age'=>66);             $this->userCache[$uid] = $user;             return $user = &$this->userCache[$uid];         }     }       public function modifyUser($uid)     {         //$user = $this->getUser($uid);      // 非引用调用         $user = &$this->getUser($uid);       // 引用调用         $this->displayArray($user);           echo "------------------\n";         $user['name'] = 'jjoe';             // 修改返回值         $this->displayArray($user);         $this->displayArray();               // 这里可看到被引用的对象值已被修改     }   }   $a = new Test(); $a->init(); $a->modifyUser(12);

　　

运行结果:

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[zcm@vm-fedora20 server]$ php test.php create a new user: name: xxy age: 66 ------------------ name: jjoe age: 66 0: Array (     [name] => joe0     [age] => 23 )   1: Array (     [name] => joe1     [age] => 24 )   2: Array (     [name] => joe2     [age] => 25 )   3: Array (     [name] => joe3     [age] => 26 )   4: Array (     [name] => joe4     [age] => 27 )   12: Array (     [name] => jjoe     [age] => 66 )