[RESOLVED] sort array

[mfacer]

this is driving me mad... I've read the manual and looked at a few posts on this site as well as through goole, and I cannot get my head around sorting an array with the following data:

Array
(
    [0] => Array
        (
            [hierarchy] => 6
            [metricID] => V20102
        )

[1] => Array
    (
        [hierarchy] => 7
        [metricID] => R20109
    )

[2] => Array
    (
        [hierarchy] => 8
        [metricID] => R20106
    )

[3] => Array
    (
        [hierarchy] => 5
        [metricID] => R20110
    )

[4] => Array
    (
        [hierarchy] => 4
        [metricID] => C20100
    )

[5] => Array
    (
        [hierarchy] => 1
        [metricID] => C20104
    )

[6] => Array
    (
        [hierarchy] => 3
        [metricID] => C20119
    )

[7] => Array
    (
        [hierarchy] => 2
        [metricID] => C20140
    )

)

I need to sort them by the "hierarchy" number. I've got the following code which doesnt seem to do anything... probably I am not using it correctly!?

usort($my_array, "cmp");

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

any help will be much appreciated!!

[Installer]

Your code works for me.

This will also work:

foreach ($my_array as $key => $val) {
    $hierarchy[$key] = $val['hierarchy'];
}
array_multisort($hierarchy, SORT_ASC, $my_array);

[mfacer]

thanks very much!! For some reason or another my code didnt work for me, but yours has done the trick nicely! 🙂