public static void Main(string[] args) { Console.WriteLine("Hit enter to start Stop Watch program."); try { var stopwatch = new StopWatch(); while (true) { var input = Console.ReadLine().ToLower().Trim(); if (string.IsNullOrWhiteSpace(input)) { Console.WriteLine("Enter 's' to start timer, 'q' to stop timer or '1' to quit program"); } else if (input == "s") { stopwatch.Start(); Console.WriteLine("The timer has started."); Console.WriteLine("Enter 'q' to stop or '1' to quit program."); } else if (input == "q") { stopwatch.Stop(); Console.WriteLine("The timer has ended."); Console.WriteLine(stopwatch.Result()); Console.WriteLine("Enter 's' to start or 1 to quit"); } else if (input == "1") { break; } } } catch (InvalidOperationException exception) { Console.WriteLine("Error: {0}", exception.Message); } catch (Exception exception) { Console.WriteLine("Error: {0}", exception.Message); } }