static void Main(string[] args) { string userOption = ""; while ((userOption = UserOption().ToUpper()) != "X") { switch (userOption) { case "1": repository.ReadAll(); break; case "2": repository.Create(UserOptionInsert()); break; case "3": repository.Update(UserOptionFind(), UserOptionUpdate()); break; case "4": repository.Delete(UserOptionFind()); break; case "5": repository.ReadByID(UserOptionFind()); break; case "C": Console.Clear(); break; default: throw new ArgumentException("Invalid command!"); } } }