static void Main(string[] args) { string menu = "\nWelcome to Program Calculator Number\n" + "this program work with 3 or 4 Arguments.\n" + "###################################################################\n" + "Argument 1 = Mode(1.Add 2.Minus 3.Multiply 4.Divide)\n" + "Argument 2 = Count Number\n" + "Argument 3 = Count Number1\n" + "###################################################################\n"; if (args.Length != 3) { Console.WriteLine("{0}", menu); } else { if (Convert.ToInt32(args[0]) == 1) { Add CountNB = new Add(); CountNB.Plus(Convert.ToDouble(args[1]), Convert.ToDouble(args[2])); } else if (Convert.ToInt32(args[0]) == 2) { Minus CountNB = new Minus(); CountNB.Minu(Convert.ToDouble(args[1]), Convert.ToDouble(args[2])); } else if (Convert.ToInt32(args[0]) == 3) { Multiply CountNB = new Multiply(); CountNB.Mul(Convert.ToDouble(args[1]), Convert.ToDouble(args[2])); } else { Divide CountNB = new Divide(); CountNB.Div(Convert.ToDouble(args[1]), Convert.ToDouble(args[2])); } } Console.ReadKey(); }