Fast FisherYatesShuffle PHP-Implementation

FisherYatesShuffle.php

<?php

final class FisherYatesShuffle
{
    /**
     * Shuffle an input sequence by Fisher-Yates-Shuffle.
     *
     * @url https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle
     *
     * @param array $input Array to shuffle
     *
     * @return array Shuffled array
     */
    public function shuffle(array $input): array
    {
        $output = $input;
        $length = count($output);

        for ($i = ($length - 1); $i >= 1; $i--) {
            $j = mt_rand(0, $i);
            $temp = $output[$i];
            $output[$i] = $output[$j];
            $output[$j] = $temp;
        }

        return $output;
    }
}