使陣列依指定的KEY值排序

function array_sort($arr,$keys,$orderby='asc'){

    $keysvalue = $new_array = array();

    foreach ($arr as $k=>$v){
        $keysvalue[$k] = $v[$keys];
    }

    if($orderby== 'asc'){
        asort($keysvalue);
    }else{
        arsort($keysvalue);
    }

    reset($keysvalue);

    foreach ($keysvalue as $k=>$v){
        $new_array[] = $arr[$k];
    }
    return $new_array;
}