PHP中把对象转数组的几个方法

    /**
     * 将对象转换成数组
     * @param $obj
     * @return mixed
     */
    function object_to_array($obj){
   
   
        $_arr = is_object($obj) ? get_object_vars($obj) :$obj;
        foreach ($_arr as $key=>$val){
   
   
            $val = (is_array($val) || is_object($val)) ? $this->object_to_array($val):$val;
            $arr[$key] = $val;
        }
        return $arr;
    }

    /**
     * 将二维数组组装成三维数组
     * @param $arr
     * @param $key
     * @return array
     */
    function changeTwoToThree($arr, $key) {
   
   
        $new = [];
        for (