static void Main() { Console.WriteLine("enter first number"); string input = Console.ReadLine(); double num1, num2; bool result = Double.TryParse(input, out num1); if (!result) { Console.WriteLine("enter a number"); return; } Console.WriteLine("enter second number"); result = Double.TryParse(Console.ReadLine(), out num2); if (!result) { Console.WriteLine("enter a number"); return; } Console.WriteLine("Enter Add,Divide"); CalculateFactory factory = new CalculateFactory(); ICalculate obj = factory.GetCalculate(Console.ReadLine()); obj.Calculate(num1, num2); Main(); }
static void Main(string[] args = null) { double num1, num2; Console.WriteLine("Enter first number ?"); var result1 = double.TryParse(Console.ReadLine(), out num1); if (!result1) { Console.WriteLine("Enter a number !!"); return; } Console.WriteLine("Enter second number ?"); var result2 = double.TryParse(Console.ReadLine(), out num2); if (!result2) { Console.WriteLine("Enter a number !!"); return; } Console.WriteLine("Choose calcualtion method (Add/Substract/Divide"); // Base classs = derive class object // Return selected object to execute relevent task (e.g. Add) var calObject = new CalculateFactory().GetCalculation(Console.ReadLine()); calObject.Calculate(num1, num2); Console.ReadLine(); Console.Clear(); Main(); }