What is meant by extensible?

What is meant by extensible?
extensible means to enhance the program with new capabilities.

In c++, extensibility can be achieved by using virtual function. now first we discuss what is virtual function in c++. " C++ virtual function is a member function of a class, whose functionality can be over-ridden in its derived classes. The whole function body can be replaced with a new set of implementation in the derived class."


Through this u can be able to promote extensibility in your program by using Virtual function. Very simple concept.