Question

So I have the following situation:

class Child : Base, IBase
{
    Response OnOperationResponse(Base base, Parameters params)
    {
       // Code code code
    }
}

public class Base
{
    protected void OnOperationResponse(Parameters params);
}

public interface IBase
{
    Response OnOperationResponse(Base base, Parameters params);
}

I am leaving a lot out, but I’ve put in the parts that are confusing me.

So, the Base class and the IBase interface both contain the same function name, but I want to use the interface’s OnOperationResponse call. Where I am getting confused, is why the developer of the library added the Base parameter into the interface? Shouldn’t the interface realize that the function is suppose to refer to this?

Am I missing something here? Or is there something further under the hood that this library is hiding?

Answer 1

Shouldn’t the interface realize that the function is suppose to refer
to this?

The parameter of type Base being passed in OnOperationResponse could be any instance of type Base – why do you make the assumption that it should be the same as the IBase instance it is being called on?

A use case (totally made up admittedly) could be augmenting or modifying a Response similar to a decorator:

class Child : Base, IBase
{
    Response OnOperationResponse(Base someBase, Parameters p)
    {
        var response = someBase.OnOperationResponse(p);
        response.Foo = "bar";
        return response;
    }
}