PHP - 组合子数组并按值排序？

Question

This is what i've got now:

Array
(
    [0] => Array
        (
            [0] => Array
                (
                    [id] => 53
                    [date] => 18 Sep 2010 10:29
                    [user] => 52
                    [post] => ytiuy
                )

            [1] => Array
                (
                    [id] => 55
                    [date] => 11 Sep 2010 11:14
                    [user] => 52
                    [post] => this is a test post :]
                )

        )

    [1] => Array
        (
            [0] => Array
                (
                    [id] => 56
                    [date] => 4 Sep 2010 03:19
                    [user] => 55
                    [post] => pppost :DD:D:D:D
                )

        )

)

I want to remove the first two "steps" in the array, and then sort the array by the 'date' value, like this:

Array
(
    [0] => Array
        (
            [id] => 56
            [date] => 4 Sep 2010 03:19
            [user] => 55
            [post] => pppost :DD:D:D:D
        )

    [1] => Array
        (
            [id] => 55
            [date] => 11 Sep 2010 11:14
            [user] => 52
            [post] => this is a test post :]
        )

    [2] => Array
        (
            [id] => 53
            [date] => 18 Sep 2010 10:29
            [user] => 52
            [post] => ytiuy
        )
)

Any ideas?

Thanks a bunch, appreciate all help! :)

EDIT: I should also mention that the amount of arrayitems will not always be the same.

Answer 1

Do you have two arrays? Or more? Are they already sorted? If so, you can use that to combine them more efficiently. If not, you probably need to sort them first.

Roughly:

1. Sort your input arrays (optionally)
2. Scan your input arrays for the lowest value, copy that value into your new array, delete the value from the input array.
3. Repeat until all your input arrays are empty.

Of course, if you don't care about performance at all you could simply combine all the arrays and then sort that.

And for sorting you may want to use: http://www.php.net/manual/en/function.sort.php#99700

@Don Kirkby: Indeed: It's basically a mergesort, but it only works on already sorted arrays. If they're both unsorted you're probably better off with combining them and using quicksort instead.