php函数xml转化数组

/**
 * xml转数组
 * @param $xml
 * @return array
 */
function xml_to_array( $xml )
{
    $reg = "/<(\\w+)[^>]*?>([\\x00-\\xFF]*?)<\\/\\1>/";
    if(preg_match_all($reg, $xml, $matches))
    {
        $count = count($matches[0]);
        $arr = array();
        for($i = 0; $i < $count; $i++)
        {
            $key = $matches[1][$i];
            $val = xml_to_array( $matches[2][$i] );  // 递归
            if(array_key_exists($key, $arr))
            {
                if(is_array($arr[$key]))
                {
                    if(!array_key_exists(0,$arr[$key]))
                    {
                        $arr[$key] = array($arr[$key]);
                    }
                }else{
                    $arr[$key] = array($arr[$key]);
                }
                $arr[$key][] = $val;
            }else{
                $arr[$key] = $val;
            }
        }
        return $arr;
    }else{
        return $xml;
    }
}