Sort multi-dimensional array - keep values of keys

Question

I want to sort my array based on the key (which is a date) - preferrably both ASC and DESC.

I have tried to use several of the methods on SO, but keep getting bad results - so I thought I would ask the question again.

I have this array:

Array
(
    [2015-05-29] => Array
        (
            [a] => 13
            [b] => 1
            [c] => 12
        )

    [2015-05-28] => Array
        (
            [a] => 10
            [b] => 1
            [c] => 1
        )

    [2015-05-27] => Array
        (
            [a] => 2
        )

    [2015-05-30] => Array
        (
            [b] => 24
            [c] => 25
        )

)

I use this function - which should work according to several posts:

uasort($days, function($a, $b) {
    return $a['points'] - $b['points'];
});

But it doesn't, as the array gets returned like this:

    Array
    (
        [2015-05-30] => Array
            (
                [b] => 24
                [c] => 25
            )

        [2015-05-27] => Array
            (
                [a] => 2
            )

        [2015-05-28] => Array
            (
                [a] => 10
                [b] => 1
                [c] => 1
            )

        [2015-05-29] => Array
            (
                [a] => 13
                [b] => 1
                [c] => 12
            )

    )

I want to have the array returned like this:

   Array
(
    [2015-05-27] => Array
        (
            [a] => 2
        )

    [2015-05-28] => Array
        (
            [a] => 10
            [b] => 1
            [c] => 1
        )

    [2015-05-29] => Array
        (
            [a] => 13
            [b] => 1
            [c] => 12
        )

    [2015-05-30] => Array
        (
            [b] => 24
            [c] => 25
        )

)

or in reverse order!

Who can help me solve this problem?

1) Post your expected output. 2) Post your original array. 3) Can't find `$a['points']` within array ? What does it means really? — Narendrasingh Sisodia, May 30 '15 at 09:41
@taapo You might want to sort using a natural order, take a look at the documentation http://php.net/manual/en/function.natsort.php and an example http://stackoverflow.com/questions/5167928/what-is-natural-ordering-when-we-talk-about-sorting — Nelson Owalo, May 30 '15 at 09:50

score 4 · Accepted Answer · answered May 30 '15 at 09:45

4

You don't need any own sorting function. Just use ksort()/krsort(), .e.g.

//ASC         //DESC
ksort($arr);  //krsort($arr);

answered May 30 '15 at 09:45

Rizier123

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Yep this'll work for him if OP is only in need of sorting the keys consisting date – Narendrasingh Sisodia May 30 '15 at 09:47
@Uchiha As I read the question this is what OP wants and with the added expected output `ksort()` is what he's looking for – Rizier123 May 30 '15 at 09:48
@Rizier, i doubt this would work, it will give hime the same result that he has posted – Nelson Owalo May 30 '15 at 09:52

Sort multi-dimensional array - keep values of keys

1 Answers1