Why do we need abstract classes in C++?

Question

I\'ve just learned about polymorphism in my OOP Class and I\'m having a hard time understanding how abstract base classes are useful.

What is the purpose of an abstr

Answer 1

Abstract classes are used to define an interface to be implemented. See some references:

http://en.wikibooks.org/wiki/C%2B%2B_Programming/Classes/Abstract_Classes