code: public function segment($num = null)
      {
          if (is_null(http()->server('REQUEST_URI')) || is_null(http()->server('SCRIPT_NAME'))) {
              return null;
          }
  
          if (! is_null($num)) {
              $uri = $this->replace(str_replace($this->base, '', http()->server('REQUEST_URI')));
              $uriA = explode('/', $uri);
              return (isset($uriA[$num]) ? reset(explode('?', $uriA[$num])) : null);
          }
  
          return null;
      }
docs: Get segments of URI.
  
  @param int $num
  
  @return string | null