static void Main(string[] args) { UIService userInteractionService = new UIService(); bool isContinue = true; while (isContinue) { userInteractionService.DisplayCommands(); var userCommand = userInteractionService.ReadCommands(); switch (userCommand) { case "list": userInteractionService.GenerateBooksList(); break; case "add": userInteractionService.AddNewBook(); break; case "delete": userInteractionService.DeleteBook(); break; case "borrow": userInteractionService.BorrowBook(); break; case "return": userInteractionService.ReturnBook(); break; case "leave": isContinue = false; userInteractionService.ExitLibrary(); break; } } }