In
C++, this optional
keyword starts declaring the protected
data members and/or
member functions. The protected members of a
class are moderately
accessible by other program parts.
It is invoked thus:
class foo
{
public:
//
protected:
protected data members
protected member functions
private:
//
}
The protected section contains data members and member functions that are not accessible to the class instances and functions that do not belong to the class (such as the main() function). Typically, the protected section contains data members and auxiliary member functions (that is, member functions that work behind the secenes to help other member functions, especially the ones declared in the public section).