How to sort a multidimensional array

[Guardian-Mage]

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)

 

How would I sort the above array by the date field ([3]). I have read about arsort and sort and all of them but I don't quite understand it. Help is greatly appreciated.

[BioBob]

array_multisort();

 

Sorry I dont have any easy examples, thats kind of a pain to work with for me and I dont mess with it much...  Probably some good ones on php.net tho...

[Psycho]

I prefer to use usort() (or uasort() if you need to maintain index associations). This is especially helpful with multidimensional arrays where you may need to add more logic than just simple sorting.

 

<?php

function sortByDate($a, $b)
{
   if ($a[3] == $b[3]) {
        return 0;
    }
    return ($a[3] < $b[3]) ? -1 : 1;
}

usort($theArray, 'sortByDate');

?>

 

EDIT: Or you can make it a one liner like so

 

<?php

function sortByDate($a, $b)
{
    return ($a[3] == $b[3])?0:(($a[3] < $b[3]) ? -1 : 1);
}

?>

[Barand]

It doesn't have to be -1,0,+1; any neg, 0 or pos will suffice, so the custom function can be simplified to

 

function sortByDate($a, $b)
{
     return ($a[3] - $b[3]) ;                      // swap a, b for DESC sort
}