Object-Oriented Design

Identifying Relationships (or Collaborations)

• Identify object relationships, e.g. what objects need to know about what other objects, what objects are part of other objects.
• Terminology: collaboration; aggregation/has-a relationships; knows-about relationships
  (Note: is-a relationships are class relationships, not object relationships. They should be handled separately, usually by inheritance.)
  Example: BlackJack Program
  • Card:
  • Deck: has cards
  • Dealer: has deck, has cards (or hand, which has cards), knows about player(s)
  • Player: has cards (or has hand, which has cards)