1. CSE 8313 Spr 2003 M. DiazFundamentals of OO Design in UML/Page-Jones1 Object Oriented Principles – Chapter 8 Encapsulation and Connascence Encapsulation –Levels –Structure Connascence –Definition –Contranascence

2. CSE 8313 Spr 2003 M. DiazFundamentals of OO Design in UML/Page-Jones2 Encapsulation Abstracting a set of constructs to a single higher level construct –Can limit access –Allows one to manage complexity –Promotes sharing

3. CSE 8313 Spr 2003 M. DiazFundamentals of OO Design in UML/Page-Jones3 Encapsulation - Levels Levels –Line of code –Procedure –Class –Component –…

4. CSE 8313 Spr 2003 M. DiazFundamentals of OO Design in UML/Page-Jones4 Encapsulation - Levels Can examine inter/intra level encapsulation –0 – 1: Fan out –1 – 0: Cohesion –1 – 1: Coupling Extends up

5. CSE 8313 Spr 2003 M. DiazFundamentals of OO Design in UML/Page-Jones5 Connascence Definition: A and B exhibit connascence –Changing A implies check/change B –Changes may require A and B both change Contrascence: A and B are independent and must be kept that way

6. CSE 8313 Spr 2003 M. DiazFundamentals of OO Design in UML/Page-Jones6 Connascence - Types Name Type Convention Algorithm Position Execution Timing Value Identity

7. CSE 8313 Spr 2003 M. DiazFundamentals of OO Design in UML/Page-Jones7 Connascence – Design Encapsulation boundaries Maintainability Abuses: “friend,” inheritance, implementation side effects