php 多维数组遍历，返回遍历处理后的数组，数组结构不不变

public function for_array($arr = array ()) {

    if(empty($arr)) {

        return false;

    } 

    foreach ( $arr as &$v) {

            if (is_array($v)) {

               $v = $this->for_array($v);

            } else {

                $v = $v.1;

            }

   }

   return $arr;     

}

public function aa() {

    $tmp_arr = array(1, array(2,3,array(4,5, array(6))));

     $temp_v = $this->for_array($tmp_arr);

       var_dump($temp_v);

}

?>