CSC/ECE 517 Fall 2010/ch1 S6 JC

CRC CARDS

  ==1. Introduction==

       Class-Responsibility-Collaborator is a simple Object oriented Analysis technique. They are also used as a successful modeling and collaborating design of a system. It basically an index card used to represent a class of objects, their behavior and their interactions. The cards are created through scenarios, based on the system requirements that model the behavior of the system

       CRC cards where introduced by Kent Beck and Ward Cunningham in there paper "A Laboratory for Teaching Object-Oriented Thinking" released in OOPLSA '89. There original purpose was to teach programmers the object-oriented paradigm.    

It consists of

  1. Class
  2. Responsibility
  3. Collaborator

   Class: A class represents an abstract characteristics of things (or Objects) and its characteristics ( or attributes). It is a user defined data type which contains all the variables, properties and methods in it. A class name is present on the top of the CRC card. Example here
   Responsibility: Responsibility indicates what a class knows or does. It is basically all the variables and methods a class has. A class can change the values of what it knows but not what other classes know. The responsibilities of a class are present on the left of the CRC card.  Example here
   Collaborator: With each responsibility you indicate which other classes you need to work with to fulfill it. This gives you some idea of the links between classes. The collaborators of a class are present on the right side of the CRC card. Example Here