Question

Having Class B that extends class A and overrides its functions can we be sure that when sending instance of (B*) as if it were type (A*) our overrides we created in class B will be called?

Answer 1

As long as the method on A is defined as virtual this will be the case for both pointers and references. For example

class A {
  virtual void Method() {
    cout << "A::Method" << endl;
  }
};

class B {
  // "virtual" is optional on the derived method although some
  // developers add it for clarity
  virtual void Method() {
    cout << "B::Method" << endl;
  }
};

void Example1(A* param) {
  param->Method();
}

void Example2(A& param) {
  param.Method();
}

void main() {
  B b;
  Example1(&b);  // Prints B::Method
  Example2(b);   // Prints B::Method
}