Classes

Terminology
• Abstract data type
• Attributes - data members
• Behaviors or operations - member functions
• Methods - another name for member functions
• Messages - member function call

• Member access specifiers
• Public - accessible by all
• Private - accessible to member functions of this class
• Instantiate by "declaring"
  Employee e;
• An example
  #include <iostream.h>
  
  class Rational {
  public:
  Rational Add (const Rational &r);
  Rational Multiply (const Rational &r);
  private:
  void SetNumerator(int number);
  void SetDenominator(int denom);
  int NumeratorValue;
  int DenominatorValue;
  };
  void main()
  {
  Rational r, s;
  
  }
• Public members are accessed by any function in the program. Public members are visible to client and thus provides a view of the class to the client.
• Private members are only accessible by member functions.
• The labels (public, private, and protected) can be repeated and apply until either another label or the } is encountered.

• Method "headers" need to indicate the class it's a member of
• Use scope resolution operator ::
  void Rational :: SetNumerator (int x)
  {
  NumeratorValue = x;
  
  }