php 数组混合GBK、UTF-8 互相转换

/**
 * 数组混合GBK、UTF-8 换转为UTF-8
 * @param unknown_type $arr
 */
static function gbktoutf8($arr){
    if(is_array($arr) && count($arr)){
        foreach($arr as $key=>$value){
            if(is_array($value)){
                $arrRs[$key] = gbktoutf8($value);
            }else{
                if(!is_utf8($value)){
                    $arrRs[$key] = iconv('GBK','UTF-8',$value);
                }else{
                    $arrRs[$key] = $value;
                }
            }
        }
        return $arrRs;
    }
    return null;
}

/**
 * 数组混合GBK、UTF-8 换转为gbk
 * @param array $arr 目标数组
 */
static function utf8togbk($arr){
    if(is_array($arr) && count($arr)){
        foreach($arr as $key=>$value){
            if(is_array($value)){
                $arrRs[$key] = utf8togbk($value);
            }else{
                //判断字符编码是否utf8字符(如果不是utf8字符则转换)
                if(is_utf8($value)){
                    $arrRs[$key] = iconv('UTF-8','GBK',$value);
                }else{
                    $arrRs[$key] = $value;
                }
            }
        }
        return $arrRs;
    }
    return 0;
}
//该片段来自于http://outofmemory.cn