``` <?php //創建單例 class Single{ public $hash; static protected $ins=null; final protected function __construct(){ $this->hash=rand(1,9999); } static public function getInstance(){ if (self::$ins instanceof self) { return self::$ins; } self::$ins=new self(); return self::$ins; } } //工廠模式 class RandFactory{ public static function factory(){ return Single::getInstance(); } } //注冊樹 class Register{ protected static $objects; public static function set($alias,$object){ self::$objects[$alias]=$object; } public static function get($alias){ return self::$objects[$alias]; } public static function _unset($alias){ unset(self::$objects[$alias]); } } Register::set('rand',RandFactory::factory()); $object=Register::get('rand'); print_r($object); ```