C++ Primer Plus, Fourth Edition

Access Control-protected

So far the class examples have used the keywords public and private to control access to class members. There is one more access category, denoted with the keyword protected. The protected keyword is like private in that the outside world can access class members in a protected section only by using public class members. The difference between private and protected comes into play only within classes derived from the base class. Members of a derived class can access protected members of a base class directly, but they cannot directly access private members of the base class. So members in the protected category behave like private members as far as the outside world is concerned but behave like public members as far as ...