public static void Main() { var person = new Person(31, "James"); Console.WriteLine(person.BuildMessage()); var doctor = new Doctor(60, "The Doctor"); doctor.UpdateAge(62); Console.WriteLine(doctor.BuildMessage()); var things = new Dictionary <string, string>(); things.Add("Marty", "McFly"); things.Add("Jason", "Thamboy"); things.Add("Roger", "Pinup-Panella"); foreach (var item in things) { Console.WriteLine(item.Key + ": " + item.Value); } }