multi level inheritance in c++

Question

Suppose there is a 3 level inheritance.

Classes A<-B<-C.

Can methods of B class access members of C which is derived from it?

Assume suitable mode of inheritance.

Can you be more specific about what you're trying to accomplish? — Brian Bi, Mar 25 '15 at 22:08
I'm not sure why the downvote. The answer is obviously no, but... and the answer is appropriate in that regard. — Félix Cantournet, Mar 25 '15 at 22:24
**Books:** https://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list — Galik, Mar 25 '15 at 23:22

score 5 · Answer 1 · answered Mar 25 '15 at 22:20

A parent class cannot access data from a child class without "tricks", e.g.

class A
{
protected:
  int m_a;
};

class B : public A
{
protected:
  int m_b;
};

B can access m_a, A cannot access m_b. To get this behaviour you can use polymorphism and an accessor function

class A
{
protected:
  virtual int GetVar() { return m_a; }
private:
  int m_a;
}

class B : public A
{
protected:
  virtual int GetVar() { return m_b; }
private:
  int m_b;
}

Now A can access m_b through calling GetVar() e.g.

void A::DoSomething()
{
  // I want to do something to the variable, 
  int myVar = GetVar();
}

Now if the instance is type A then A::GetVar() is called, if the instance is type B then B::GetVar() will be called instead

multi level inheritance in c++

1 Answers1