Sort array string-type keys by a custom alphabet?

Question

I want to sort arrays by key in php, but the alphabet that I'm using is not the normal English alphabet -- it's a self-created alphabet. Is this possible?

My alphabet is:

$alphabet = "AjawbpfmnrhHxXsSqkgtTdD =";

The array is like this:

Array (
   [=k_0] => Array(
       [0] => DI.3,2 &dwA-nTr& @Hrw@
       [1] => mA
       [2] => =k
       [3] => Sfj,t
       [4] => =k
       [5] => pXr
       )
   [aA_2] => Array(
       [0] => DI.7,4 &dwA-nTr& @Hrw-smA-tA,wj@
       [1] => snD
       [2] => aA
       [3] => Sfj,t
       [4] => jt
       [5] => jt,w
       )
  [sqA_1] => Array(
       [0] => DI.6,18 &dwA-nTr& @nswt@
       [1] => ra
       [2] => sqA
       [3] => Sfj,t
       [4] => =s
       [5] => r
       )
   );

So if I sort this array following my alphabet then the array with the key [=k_0] should be at the end.

Answer 1

You can use the usort() function and provide your own sorting logic.

See php.net for an example.

Edit: use uksort, not usort. See http://www.php.net/manual/en/function.uksort.php. Thanks @Darien!

A slightly modified example from php.net - the original code with an $alphabet mapping added:

function cmp($a, $b)
{
    // custom sort order - just swapps 2 and 3.
    $alphabet = array (1 => 1, 2 => 3, 3 => 2, 4 => 4, 5 => 5, 6=> 6);

    if ($alphabet[$a] == $alphabet[$b]) {
        return 0;
    }
    return ($alphabet[$a] < $alphabet[$b]) ? -1 : 1;
}

$a = array(3 => 'c' , 2 => 'b', 5 => 'e', 6 => 'f', 1=>'a');
uksort($a, "cmp");

foreach ($a as $key => $value) {
    echo "$key: $value\n";
}