main.dart

class Vehicle {
  String? make;
  String? model;
  int? manufactureYear;
  int? vehicleAge;
  String? color;

  int get age {
    return vehicleAge ?? 0;
  }

  void set age(int currentYear) {
    vehicleAge = currentYear - (manufactureYear ?? 2020);
  }

  // We can also eliminate the setter and just use a getter.
  //int get age {
  //  return DateTime.now().year - manufactureYear;
  //}

  Vehicle({this.make,this.model,this.manufactureYear,this.color,});
}

void main() {
  Vehicle v = Vehicle();
  v.age = 2022;
  print(v.age);
}