Forget URL id in controller using laravel 5.1

we can forget URL id in controller using codeginiter

public function grid($id)
    {  
      $sub_id = $this->uri->segment(3);
    }

how we can forget URL id in controller using laravel 5.1 ???

public function grid(Request $request, $id)
    {  
       // how we can forget this ($id) here
    }

via Chebli Mohamed