PHP中多维数组值的排序或位置

我想根据点数对下面的数组进行排序，重复的点数将被相同的排序。你知道我将如何完成这项任务吗

Array
(
[6] => Array
    (
        [points] => 0
        [details] => Array
            (
                [name] => name 1
                [rank] => 
            )

    )

[220] => Array
    (
        [points] => 794
        [details] => Array
            (
                [name] => name 2
                [rank] => 
            )

    )

[369] => Array
    (
        [points] => 1002
        [details] => Array
            (
                [name] => name 3
                [rank] => 
            )

    )

[138] => Array
    (
        [points] => 1239
        [details] => Array
            (
                [name] => name 4
                [rank] => 
            )

    )

[778] => Array
    (
        [points] => 1302
        [details] => Array
            (
                [name] => name 5
                [rank] => 
            )

    )
)

大概是这样的：

$sort=array();
foreach($array as $key=>$v){$sort[$key]=$v['points'];}
sort($sort);
$newArray=array();
$i=0; $points=0;
foreach($sort as $key=>$v){
    $i++;
    if($v['points']>$points){$i++; $points=$v['points'];
    $newArray[$key]=$array['key'];
    $newArray[$key]['rank']=$i;
}
$array=$newArray;

---

谢谢你的回答。但我的数组已经按点排序了。我只想给数组添加秩值。我将如何做到这一点。