Why do we need virtual functions in C++?

Question

I\'m learning C++ and I\'m just getting into virtual functions.

From what I\'ve read (in the book and online), virtual functions are functions in the base class that

Answer 1

You have to distinguish between overriding and overloading. Without the virtual keyword you only overload a method of a base class. This means nothing but hiding. Let's say you have a base class Base and a derived class Specialized which both implement void foo(). Now you have a pointer to Base pointing to an instance of Specialized. When you call foo() on it you can observe the difference that virtual makes: If the method is virtual, the implementation of Specialized will be used, if it is missing, the version from Base will be chosen. It is best practice to never overload methods from a base class. Making a method non-virtual is the way of its author to tell you that its extension in subclasses is not intended.