工厂模式

interface mysql{



    public function connect();

}



class mysqli2 implements mysql{



    public function connect(){

        echo 'mysqli';

    }

}



class pdo2 implements mysql{



    public function connect(){

        echo 'pdo';

    }

}





class mysqlFactory{





    static public function factory($class_name){

        return new $class_name();

    }



}



$obj = mysqlFactory::factory('pdo2');

$obj->connect();