Calling virtual functions inside constructors

Question

Suppose I have two C++ classes:

class A
{
public:
  A() { fn(); }

  virtual void fn() { _n = 1; }
  int getn() { return _n; }

protected:
  int _n;
};

clas         


        

Answer 1

I am not seeing the importance of the virtual key word here. b is a static-typed variable, and its type is determined by compiler at compile time. The function calls would not reference the vtable. When b is constructed, its parent class's constructor is called, which is why the value of _n is set to 1.