Question

Here is a skeleton code:

class C{
  callMe(){}
};

class A{
  // How to use callMe()
};

class B : C {
  callMe();
  A a;
};

In this example class B extends class C, so it can call callMe() method. But I need to use callMe() using class A given that class A can not extend class C. I wonder how?

Answer 1

you need to make A contain an object of type C.

class A
{
 private:
   C objC;

 public:
   void WhateverMethod() { objC.CallMe(); }

};

Also, the syntax for inheritance is

class B : C{

};

If you want B to simply have access to CallMe(), then you do not need to redefine it in B. It will inherit it from C. If you want B to override CallMe then you need to do this:

class C
{
  public:
    virtual void CallMe() { //definition }

};

class B : public C
{
 public:
   void CallMe() { //redefine it here }

};

Note, I assume from your syntax errors that you are a JAVA programmer. Methods are not automatically marked as virtual in C++, you have to mark them as virtual if you want to use polymorphism, and you have to use them from a pointer for it to work.