Overview public protected in C + + the usage of the private friend keyword _c language

A variable in a C + + class that has the following keyword as the modifier.

1. Public: Access is available anywhere in the program.

2 Protected: Only the class itself and its derived classes and their friend functions, the friend class can access.

3 Private: Only the class itself and its friends function, the friend class can be accessed.

4 friend: Used to define friend class of friends function. A normal function declared in a class, preceded by a friend modifier, that can access all members of the class, including private members.

The following is a look at the C + + Public Private protected keyword

1, when the use of these three keywords inside the class, to indicate access rights:

Public: can be accessed arbitrarily.

Protected: Only child classes and member functions of this class are allowed to be accessed.

Private: Only member functions of this class are allowed to be accessed.

2. When accessed in the inheritance hierarchy of a class:

Public: access rights for base class members are not changed.

Protected: The public member of the base class is a protected member of the subclass, and the access rights of the other members are unchanged.

Private: The access rights of all members of the base class in the subclass become private.

The above is a small series to introduce the overview of C + + in the public protected private friend keyword usage, I hope to help you, if you have any questions please give me a message, small series will promptly reply to everyone. Here also thank you very much for the cloud Habitat Community website support!