Hiding the implementation (cont'd)

In Listing 3, the private data members and functions can be accessed only by other member functions of the class.

They cannot be accessed by program statements outside the class.

Thus, they are hidden from the using program.

Listing 3. Encapsulation.

class Date{ //--- Implementation is private by default int month, day, year;//private data members ...//other private data members or functions public://the class interface is made public Date(int mo,int da,int yr);//public constructor Date operator+(int n);//public overloaded operator ...//other public interface functions };// note the required semicolon