static void Main(string[] args) { String x; Console.WriteLine("Enter A Text"); String s = Console.ReadLine(); Class1 obj = new Class1(s); Console.Write(obj.get()); do { Console.Write("\n1.Add\n2.Sub\n3.Mul\n4.Div\n"); Console.WriteLine("Enter Choice:"); int val = Convert.ToInt32(Console.ReadLine()); while (!obj.Calculation(val)) { Console.Write("Enter PreValue:"); int pre = Convert.ToInt32(Console.ReadLine()); Console.Write("Enter PostValue:"); int post = Convert.ToInt32(Console.ReadLine()); obj.CalculationSwitch(val, pre, post); break; } Console.WriteLine("Do you want to continue? Y/N"); x = Console.ReadLine(); } while (x.Equals("y") | x.Equals("Y")); Console.Read(); }