static void Main(string[] args) { bool operation = true; while (operation) { Console.Clear(); Console.WriteLine("Calculator App By: 3 mands gruppen."); Console.WriteLine("Choose an action. Follwed by Enter.\n"); Console.WriteLine("Add : 1 \n" + "Subtract : 2\n" + "Multiply : 3\n" + "Divide : 4\n" + "Power : 5\n" + "Factorial : 6 \n" + "Exit program : 7"); string act = Console.ReadLine(); Console.Clear(); int value1 = 0; int value2 = 0; switch (act) { case "1": try { Console.WriteLine("Enter your first value: followed by Enter."); value1 = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("Enter your second value: followed by Enter."); value2 = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("The solution is :" + Calculator.Add(value1, value2)); } catch { Console.WriteLine("Not a valid value!"); Console.ReadKey(); } break; case "2": try { Console.WriteLine("Enter your first value: followed by Enter."); value1 = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("Enter your second value: followed by Enter."); value2 = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("The solution is :" + Calculator.Subtract(value1, value2)); Console.ReadKey(); } catch { Console.WriteLine("Not a valid value!"); Console.ReadKey(); } break; case "3": try { Console.WriteLine("Enter your first value: followed by Enter."); value1 = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("Enter your second value: followed by Enter."); value2 = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("The solution is :" + Calculator.Multy(value1, value2)); Console.ReadKey(); } catch { Console.WriteLine("Not a valid value!"); Console.ReadKey(); } break; case "4": try { Console.WriteLine("Enter your first value: followed by Enter."); value1 = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("Enter your second value: followed by Enter."); value2 = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("The solution is :" + Calculator.Div(value1, value2)); Console.ReadKey(); } catch { Console.WriteLine("Not a valid value!"); Console.ReadKey(); } break; case "5": try { Console.WriteLine("Enter your first value: followed by Enter."); value1 = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("Enter your second value: followed by Enter."); value2 = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("The solution is :" + Calculator.Power(value1, value2)); Console.ReadKey(); } catch { Console.WriteLine("Not a valid value!"); Console.ReadKey(); } break; case "6": try { Console.WriteLine("Enter your value: followed by Enter."); value1 = Convert.ToInt32(Console.ReadLine()); Console.WriteLine("The solution is :" + Calculator.Fac(value1)); Console.ReadKey(); } catch { Console.WriteLine("Not a valid value!"); Console.ReadKey(); } break; case "7": try { Console.WriteLine("End of operation"); operation = false; Console.ReadKey(); } catch { } break; default: Console.WriteLine("You have to enter an invalid option!"); Console.ReadKey(); break; } } }