public static void Main()
string UserDecision = string.Empty;
Console.WriteLine("Please select your coffee: 1 - Small, 2 - Medium, 3 - Large"); UserChoice = int.Parse(Console.ReadLine());
Console.WriteLine("Your choice {0} is invalid", UserChoice); } while (UserChoice != 1 && UserChoice != 2 && UserChoice != 3);
Console.WriteLine("Do you want to buy another coffee - Yes or No?"); UserDecision = Console.ReadLine().ToUpper();
if (UserDecision != "YES" && UserDecision != "NO");
Console.WriteLine("Your choice {0} is invalid. Please try again...", UserDecision); } while (UserDecision != "YES" && UserDecision != "NO");
while (UserDecision.ToUpper() != "NO");
Console.WriteLine("Thank you for shoppping with us."); Console.WriteLine("Bill Amount = {0}", TotalCoffeeCost);
