ord

<?php     private static function convertAlphaVersionToIntVersion($alpha)

    {

        return strlen($alpha) * (-ord('a') + 1) + array_sum(array_map('ord', str_split($alpha)));

    }

<?php         for ($i = 0; isset($string[$i]); $i++) {

            $character = $string[$i];

            if (!ctype_alnum($character) && !in_array($character, array('-', '_'), true)) {

                $character = '%' . sprintf('%02X', ord($character));

            }

            $encoded .= $character;

        }