PHP order array by date? [duplicate]

Answer 1

He was considering having the date as a key, but worried that values will be written one above other, all I wanted to show (maybe not that obvious, that why I do edit) is that he can still have values intact, not written one above other, isn't this okay?!

<?php
 $data['may_1_2002']=
 Array(
 'title_id_32'=>'Good morning', 
 'title_id_21'=>'Blue sky',
 'title_id_3'=>'Summer',
 'date'=>'1 May 2002'
 );

 $data['may_2_2002']=
 Array(
 'title_id_34'=>'Leaves', 
 'title_id_20'=>'Old times',
  'date'=>'2 May   2002 '
 );


 echo '<pre>';
 print_r($data);
?>

Answer 2

You don't need to convert your dates to timestamp before the sorting, but it's a good idea though because it will take more time to sort without it.

$data = array(
    array(
        "title" => "Another title",
        "date"  => "Fri, 17 Jun 2011 08:55:57 +0200"
    ),
    array(
        "title" => "My title",
        "date"  => "Mon, 16 Jun 2010 06:55:57 +0200"
    )
);

function sortFunction( $a, $b ) {
    return strtotime($a["date"]) - strtotime($b["date"]);
}
usort($data, "sortFunction");
var_dump($data);

Answer 3

I recommend using DateTime objects instead of strings, because you cannot easily compare strings, which is required for sorting. You also get additional advantages for working with dates.

Once you have the DateTime objects, sorting is quite easy:

usort($array, function($a, $b) {
  return ($a['date'] < $b['date']) ? -1 : 1;
});

Answer 4

Use usort:

usort($array, function($a1, $a2) {
   $v1 = strtotime($a1['date']);
   $v2 = strtotime($a2['date']);
   return $v1 - $v2; // $v2 - $v1 to reverse direction
});