为什么在C ++中一次调用基本方法

Question

I have a situation similar to below (code is NOT exact, just to get my point across). When I call DA() I expect the word "Desc" to be printed, but instead "Base" is printed.

class Base {
public:
  void A() { B(); }
  virtual void B() { cout << "Base"; }
}

class Descendant : public Base {
public:
  virtual void B() overriden { cout << "Desc"; }
}

main () {
  Descendant D;
  D.A();
}

There must be something conceptual I'm missing here. Should DA() cause "Desc" to be printed? If not, why?

Answer 1

There is an important error in the question. The method A is in fact the constructor of the Base class. And it makes sense that the constructor can't call any methods (even virtual) of derived classes since those derived classes don't exist yet.

When A is a non-ctor, it works as expected.