Question

Jumping into the question straight away.

Scenario-Steps:

1) I defines an interface

IMathBase 
{
   void Add(int a , int b);
   void Sub(int a, int b);
}

2) A Concrete class PlusMinus implements IMathBase.

3) A Concrete class PlusMinusDiv implements IMathBase. PlusMinusDiv adds another function void Div(int a, int b)

4) IMathBase mathBase = new PlusMinusDiv();

5) mathBase.Div(10,20);

I know the step 5 is invalid. What is the best way to deal with the above situation[ to add a new method to a concrete class which implements a common interface]?

Thanks in advance.

Regards,

Joe

Answer 1

Either

PlusMinusDiv mathBase = new PlusMinusDiv();
mathBase.Div(10,20);

or

IMathBase mathBase = new PlusMinusDiv();
((PlusMinusDiv)mathBase).Div(10,20);