Class Diagrams

+

public

-

private

#

protected

~

package

• Association: General relationship

• Aggregation (hollow diamond): "has-a", parts can exist independently

• Composition (filled diamond): Strong ownership, parts die with whole

• Generalization (triangle arrow): Inheritance

• General relationship

• B inherits from A

• A is a generalization

• B is a concrete implementation/realization of A

• A and B call eachother

• A can call B’s methods

• But not visa versa

• Aggregation

• A has one or more instances of B

• B can survive if A is disposed

• Composition

• A has one or more instances of B

• B cannot survive if A is disposed

Building a Class Diagram

• Identify classes

• Identify attributes/properties

• Identify operations

• Indentify association types