static void Main(string[] args)
{
Console.WriteLine("***** Extending an Interface *****\n");
MyCalc c = new MyCalc();
Console.WriteLine("1 + 2 = {0}", c.Add(1, 2));
Console.WriteLine("1 - 2 = {0}", c.Subtract(1, 2));
Console.WriteLine("30 - 9 = {0}", ((IBasicMath) c).Subtract(30, 9));
Console.ReadLine();
}
static void Main(string[] args)
{
Console.WriteLine("***** Extending an interface *****\n");
// Call IBasicMath members from MyCalc object.
MyCalc c = new MyCalc();
Console.WriteLine("1 + 2 = {0}", c.Add(1, 2));
Console.WriteLine("1 - 2 = {0}", c.Subtract(1, 2));
// Can also cast into IBasicMath to invoke extension.
Console.WriteLine("30 - 9 = {0}",
((IBasicMath)c).Subtract(30, 9));
// This would NOT work!
// IBasicMath itfBM = new IBasicMath();
// itfBM.Subtract(10, 10);
Console.ReadLine();
}