518     public static function mb_strpos($haystack, $needle, $offset = 0, $encoding = null)  argument
522             return strpos($haystack, $needle, $offset);
525         $needle = (string) $needle;
526         if ('' === $needle) {
536         return iconv_strpos($haystack, $needle, $offset, $encoding);
539     public static function mb_strrpos($haystack, $needle, $offset = 0, $encoding = null)  argument
543             return strrpos($haystack, $needle, $offset);
550                 if (0 > $offset += self::mb_strlen($needle)) {
559         $pos = '' !== $needle || 80000 > \PHP_VERSION_ID
560             ? iconv_strrpos($haystack, $needle, $encoding)
663     public static function mb_stripos($haystack, $needle, $offset = 0, $encoding = null)  argument
665         [$haystack, $needle] = str_replace(self::SIMPLE_CASE_FOLD[0], self::SIMPLE_CASE_FOLD[1], [
667             self::mb_convert_case($needle, \MB_CASE_LOWER, $encoding),
670         return self::mb_strpos($haystack, $needle, $offset, $encoding);
673     public static function mb_stristr($haystack, $needle, $part = false, $encoding = null)  argument
675         $pos = self::mb_stripos($haystack, $needle, 0, $encoding);
680     public static function mb_strrchr($haystack, $needle, $part = false, $encoding = null)  argument
684             $pos = strrpos($haystack, $needle);
686             $needle = self::mb_substr($needle, 0, 1, $encoding);
687             $pos = iconv_strrpos($haystack, $needle, $encoding);
693     public static function mb_strrichr($haystack, $needle, $part = false, $encoding = null)  argument
695         $needle = self::mb_substr($needle, 0, 1, $encoding);
696         $pos = self::mb_strripos($haystack, $needle, $encoding);
701     public static function mb_strripos($haystack, $needle, $offset = 0, $encoding = null)  argument
704         $needle = self::mb_convert_case($needle, \MB_CASE_LOWER, $encoding);
707         $needle = str_replace(self::SIMPLE_CASE_FOLD[0], self::SIMPLE_CASE_FOLD[1], $needle);
709         return self::mb_strrpos($haystack, $needle, $offset, $encoding);
712     public static function mb_strstr($haystack, $needle, $part = false, $encoding = null)  argument
714         $pos = strpos($haystack, $needle);
777     public static function mb_substr_count($haystack, $needle, $encoding = null)  argument
779         return substr_count($haystack, $needle);