Question

I know the interface is working. When I started coding in my project, I got this doubt in my mind. Can anyone clarify ?

Answer 1

As I understand, you want to know why we can’t specify constructor’s signature as well as other object’s methods, like

    interface IApp
    {
         void App(int i, int j);
    }
    class App : IApp
    {
         // You want constructor to be only with 2 parameters
         public void App(int i, int j){ }
    }

It can’t be done because at first, all interface methods should be implemented as public but constructors can be set as private, and at second, method void App(..) will be constructor only for class App, for another class it will be another method.

So in common, if you want to specify constructor with known parameters, try to use abstract base classes.