unyx / utils

     * @param   string|null $encoding   The encoding to use.

     * @return  int                     The index of the first occurrence if found, -1 otherwise.

     */

    public static function indexOf(string $haystack, string $needle, int $offset = 0, bool $strict = true, string $encoding = null) : int

    {

        $func     = $strict ? 'mb_strpos' : 'mb_stripos';

        $encoding = $encoding ?: static::encoding($haystack);

        if (false === $result = $func($haystack, $needle, $offset, $encoding)) {

            return -1;

        }

        return $result;

    }

    /**

     * Returns the index (0-indexed) of the last occurrence of $needle in the $haystack.

     * @param   string  $encoding   The encoding to use.

     * @return  int                 The index of the last occurrence if found, -1 otherwise.

     */

    public static function indexOfLast(string $haystack, string $needle, int $offset = 0, bool $strict = true, string $encoding = null) : int

    {

        $func     = $strict ? 'mb_strrpos' : 'mb_strripos';

        $encoding = $encoding ?: static::encoding($haystack);

        if (false === $result = $func($haystack, $needle, $offset, $encoding)) {

            return -1;

        }

        return $result;

    }

    /**

     * Inserts the given $needle into the $haystack at the provided offset.