php syntax error

i want here make loop and put result from request in array

class InsertimgController extends Controller
{

    public function insertimg(Request $request){
            $y= count($request->all())-1;
            $x = [
                for($z=1; $z<=$y; $z++){
                    $request[$z];
                }];
                return [array_sum($x) , $y];
    }
}