Usage of keyword virtual

Question

Hi,
Got a basic question.
Is the usage of keyword "virtual" optional when declaring the methods in the derived class?
Eg:
class C {
public:
virtual void vmethod();
class D : public C
public:
void vmethod(); // missing keyword virtual. is it ok?
TIA
Satya

Answer 1

If the declaration of the derived-class function is identical to the base-class version, the "virtual" keyword is optional. If the declarations are not the same, the derived-class function will not be a virtual function unles you declare it virtual. Example:
class Base {
public:
   virtual int f(int);
   virtual int g(int);
class Derived : public Base {
public:
  int f(int, int); // not virtual
  int g(int); // implicitly virtual
};