Overriding non-virtual methods

by

Yep, you are misunderstanding a little.

The method of the same name on the derived class will hide the parent method in this case. You would imagine that if this weren’t the case, trying to create a method with the same name as a base class non-virtual method should throw an error. It is allowed and it’s not a problem – and if you call the method directly as you have done it will be called fine.

But, being non-virtual, C++ method lookup mechanisms that allow for polymorphism won’t be used. So for example if you created an instance of your derived class but called your ‘Display’ method via a pointer to the base class, the base’s method will be called, whereas for ‘vDisplay’ the derived method would be called.

For example, try adding these lines:

Base *b = &ba;
b->Display();
b->vDisplay();
b = &de;
b->Display();
b->vDisplay();

…and observe the output as expected:

Base: Non-virtual display.
Base: Virtual display.
Base: Non-virtual display.
Derived: Virtual display.

More Related Contents:

  1. Why does an overridden function in the derived class hide other overloads of the base class?
  2. Calling virtual functions inside constructors
  3. C++ “virtual” keyword for functions in derived classes. Is it necessary?
  4. Can I call a base class’s virtual function if I’m overriding it?
  5. C++ virtual function return type
  6. What is the ‘override’ keyword in C++ used for? [duplicate]
  7. Is the ‘override’ keyword just a check for a overridden virtual method?
  8. Overriding a Base’s Overloaded Function in C++ [duplicate]
  9. What are the differences between overriding virtual functions and hiding non-virtual functions?
  10. Override a member function with different return type
  11. Inheritance and method overloading
  12. Force all classes to implement / override a ‘pure virtual’ method in multi-level inheritance hierarchy
  13. Differentiate between function overloading and function overriding
  14. Overriding public virtual functions with private functions in C++
  15. Overriding static variables when subclassing
  16. C++ inheritance and function overriding
  17. How to enforce the ‘override’ keyword?
  18. Override and overload in C++
  19. C++ virtual override functions with same name
  20. Can I get polymorphic behavior without using virtual functions?
  21. Using includes with c++ shared libraries
  22. Why is my program slow when looping over exactly 8192 elements?
  23. how to provide a swap function for my class?
  24. Inspecting standard container (std::map) contents with gdb
  25. How to know if a pointer points to the heap or the stack?
  26. How to achieve “virtual template function” in C++
  27. Compare two float variables in C++
  28. How to output float to cout without scientific notation or trailing zeros?
  29. Visual Studio debugger error: Unable to start program Specified file cannot be found
  30. Visual Studio Warning C4996

Leave a Comment