What does it mean to declare a

1.      member function as a virtual

A:

(a) C++ virtual function is member function of any class, whose functionality may be over- ridden in its derived classes. The entire function body might be replaced along with a new set of implementation in derived class. The concept of c++ virtual functions is distinct from C++ Function overloading. The difference among a virtual member function and a non-virtual c++ member function is, the non-virtual member functions are determined at compile time. This mechanism is called as static binding. Whereas the c++ virtual member functions are determined during run-time. This mechanism is called as dynamic binding.