1. CRC Cards: Overview Emerson Murphy-Hill Creative Commons Attribution 4.0 License. Material Produced by NCSU Software Engineering Faculty.

2. Introduction to CRC Cards CRC Card = Class Responsibility Collaboration Card Purpose: interactively brainstorm an initial design of a program or program segment to help developers think in an object-oriented way avoid thinking about implementation details too early Invented in 1989 by Kent Beck and Ward Cunningham

3. CRC Cards Class – the name of an OO class (a good descriptive noun) Responsibility – the things the OO class does (behavior responsibility) Collaborator – the relationship the class has with other classes Class Name Main Responsibility Description Responsibilities Collaborators...... 4 X 6 (or 3 X 5) Index card Class attributes (what the class must know about itself – knowledge responsibility) on the back of the card

4. Slide 4 An Example CRC Card - Front @Dennis, Wixom, & Roth Main Responsibility A patient makes appointments, review or configure insurance information, and provides medical history

5. Slide 5 An Example CRC Card - Back @Dennis, Wixom, & Roth

6. CRC Cards  What next? Class Name Main Responsibility Description Responsibilities Collaborators...... Turn these cards into your class diagram Card  Class Responsibilities  Methods Collaborators  Associations (need to have instances of collaborating classes) Data members on the card back  Attributes