Syntax

• virtual void f();
• virtual void g() = 0;
• C++11 or later:
  • virtual void h() override;
  • void i() override;
  • virtual void j() final;
  • void k() final;

Remarks

• Only non-static, non-template member functions can be virtual.
• If you are using C++11 or later, it is recommended to use override when overriding a virtual member function from a base class.
• Polymorphic base classes often have virtual destructors to allow a derived object to be deleted through a pointer to the base class. If the destructor were not virtual, such an operation leads to undefined behavior[expr.delete] §5.3.5/3 .

Using override with virtual in C++ 11

Virtual vs non-virtual member functions

Final virtual functions

Behaviour of virtual functions in constructors and destructors

Pure virtual functions