Sorting arrays within an array in PHP by datetime

Question

I currently have a problem within PHP where I want to sort these posts by their creation date so that they can then be shown in descending order. I have been looking for a PHP function to do this but have had no luck.

Is there an easy solution to this? Any idea will be greatly appreciated :)

array
      0 => 
        array
          'post_id' => string '1' (length=1)
          'user_id' => string '3' (length=1)
          'post' => string 'this is a post' (length=14)
          'created' => string '2012-04-05 20:11:38' (length=19)
     1 => 
        array
          'post_id' => string '2' (length=1)
          'user_id' => string '2' (length=1)
          'post' => string 'this is a post' (length=14)
          'created' => string '2012-04-05 20:11:38' (length=19)
     2 => 
        array
          'post_id' => string '3' (length=1)
          'user_id' => string '5' (length=1)
          'post' => string 'this is a post' (length=14)
          'created' => string '2012-04-05 20:11:38' (length=19)

Answer 1

Try this:

<?php
$a=array(
      0 => 
        array(
          'post_id' => '1',
          'user_id' => '3',
          'post' => 'this is a post',
          'created' => '2012-04-05 20:11:40'
          ),
     1 => 
        array(
          'post_id' => '2',
          'user_id' => '2',
          'post' => 'this is a post',
          'created' => '2012-04-05 20:11:39'
          ),
     2 => 
        array(
          'post_id' => '3',
          'user_id' => '5',
          'post' => 'this is a post',
          'created' => '2012-04-05 20:11:38'
          )
);
function cmp($a,$b){
    return strtotime($a['created'])<strtotime($b['created'])?1:-1;
};

uasort($a,'cmp');
print_r($a);
?>