Sorting array of associative arrays

Question

I have an array in following format:

array( 
    [0]=> array(
        [0]=> array ( 
            ["ID"]=> 118
            ["post_date"]=> "2014-04-28 07:27:37" 
            ["post_title"]=> "Title 1"
        )
        [1]=> array ( 
            ["ID"]=> 119
            ["post_date"]=> "2014-04-29 07:27:37" 
            ["post_title"]=> "title 2"
        )
    )
    [1]=> array(
        [0]=> array ( 
            ["ID"]=> 135
            ["post_date"]=> "2014-04-28 06:37:37" 
            ["post_title"]=> "Title 3"
        )
        [1]=> array ( 
            ["ID"]=> 148
            ["post_date"]=> "2014-04-25 07:27:37" 
            ["post_title"]=> "Title 4"
        )
    )
    [2]=> array(
        [0]=> array ( 
            ["ID"]=> 135
            ["post_date"]=> "2014-04-24 06:37:37" 
            ["post_title"]=> "Title 5"
        )
        [1]=> array ( 
            ["ID"]=> 148
            ["post_date"]=> "2014-04-25 09:21:37" 
            ["post_title"]=> "Title 6"
        )
    )
)

Now I need to sort this using post_date and show them in DESC order. This is in PHP.

I am not sure how to sort this. Can anybody please help me with this sorting?

This is how I want to show the output:

title 2
Title 1
Title 3
Title 6
Title 4
Title 5

possible duplicate of [Sort Multi-dimensional Array by Value](http://stackoverflow.com/questions/2699086/sort-multi-dimensional-array-by-value) — Nazin, May 04 '14 at 15:45
"sort this using `post_date`" - which `post_date`? Each array element ultimately contains two, which appear to differ unpredictably. — Hammerite, May 04 '14 at 15:47
@Nazin I have got an extra level deeper, than that one. But I will try with that answer. — тнє Sufi, May 04 '14 at 16:06
@Hammerite I need to sort them based on the post_date key. Please check the updated post, for how I want it to show output. Thanks. — тнє Sufi, May 04 '14 at 16:06
How are you generating this data? I think you'd have an easier time sorting an array of arrays, rather than an array of arrays of arrays. — WinterMute, May 04 '14 at 16:15
So you are saying you want to flatten the top-level array and then sort using the `post_date`s of the flattened array? This is really two operations that need to be composed together. The flattening step can be accomplished using a loop. The sorting can be achieved using Petah's answer to the question linked by Nazin. — Hammerite, May 04 '14 at 16:46
@Hammerite thanks a lot for the flattening tips. I have flattened the array, and was able to sort it using `usort`. I have added my code as answer. — тнє Sufi, May 05 '14 at 14:29

score 2 · Accepted Answer · answered May 05 '14 at 14:36

Okay, I have solved it by flattening the array and then applying usort. This is how I have done it:

$query_results; //this is my main array
$flatten_array =array();
foreach ($query_results as $data) {
    foreach($data as $flatten_data) {
        $flatten_array[] = $flatten_data;
    }
}

function cpt_array_sort($a, $b) {
    return strtotime($b->post_date) - strtotime($a->post_date);
}

usort($flatten_array, 'cpt_array_sort');

Sorting array of associative arrays

1 Answers1