dayAfterBirthStr property Null safety

Implementation

String get dayAfterBirthStr {
  if (birth != null) {
    DateTime _today = Helper().convertDateTimeToMidnight(DateTime.now());
    DateTime _birth = Helper().convertDateTimeToMidnight(birth!);
    int result = _today.difference(_birth).inDays + 1;
    return result > 0 ? result.toString() : "-";
  } else {
    return "-";
  }
}