PHP中怎么把对象转换为关联数组

/**

* 对象转关联数组

* @author

* @param object $obj

* @return array

*/

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;

}