A substitute for the php shuffle() function using mt_rand(), i.e. the Mersenne Twister algorithm - for improved randomness

mt_shuffle.php

<?php

function mt_shuffle(&$array) {
    $randArr = [];
    $arrLength = count($array);

    // while my array is not empty I select a random position
    while (count($array)) {
        //mt_rand returns a random number between two values
        $randPos = mt_rand(0, --$arrLength);
        $randArr[] = $array[$randPos];

        /* If number of remaining elements in the array is the same as the
         * random position, take out the item in that position,
         * else use the negative offset.
         * This will prevent array_splice removing the last item.
         */
        array_splice($array, $randPos, ($randPos == $arrLength ? 1 : $randPos - $arrLength));
    }

    $array = $randArr;
    return;
}