PHP Sort a multidimensional array by element containing date

Question

I have an array such as:

Array
(
[0] => Array
    (
        [id] => 2
        [type] => comment
        [text] => hey
        [datetime] => 20         


        

Answer 1

For 'd/m/Y' dates:

usort($array, function ($a, $b, $i = 'datetime') { 
    $t1 = strtotime(str_replace('/', '-', $a[$i]));
    $t2 = strtotime(str_replace('/', '-', $b[$i]));

    return $t1 > $t2;
});

where $i is the array index