Exercise: Access Methods for Members

Description

In exercise Exercise: Simple Method (Users Age By n Years), you had to modify class User: you removed the const specifier from the age member. age is still public, which gives everybody permission to write to age - not only class methods.

Introduce a private section, and put all (not just age) into that section. This will break all code that accesses members directly.

Fix that: introduce access methods for the members.