private static void staticFunctionDemo()
        {
            int    v1  = GetInteger("Enter an integer");
            int    v2  = GetInteger("Enter an integer");
            string op  = GetString("Enter the operator: + or - or * or /");
            double res = 0;

            switch (op)
            {
            case "+":
                res = Arithematic.AddFunc(v1, v2);
                break;

            case "-":
                res = Arithematic.SubFunc(v1, v2);
                break;

            case "*":
                res = Arithematic.MulFunc(v1, v2);
                break;

            default:
                break;
            }
            Console.WriteLine($"The result of this operation is {res}");
        }
        private static void multiplreturnValueDemo()
        {
            //declare all the out parameters...
            double res1, res2, res3, res4 = 123 /*It is ref value*/;

            Arithematic.GetAllValues(123, 0, out res1, out res2, out res3, ref res4);
            Console.WriteLine("The added value is " + res1);
            Console.WriteLine("The Subtracted value is " + res2);
            Console.WriteLine("The Multiplied value is " + res3);
            Console.WriteLine("The Divided value is " + res4);
        }