UML Quick Reference - Class Diagram

Source https://www.visual-paradigm.com/guide/uml-unified-modeling-language/uml-class-diagram-tutorial/, Reference http://ifeve.com/uml-intro/

Class Diagram

Class Notation

1. Class Name
2. Class Attributes
3. Class Operations (Method)

Visibility

• + denotes public attributes or operations
• - denotes private attributes or operations
• # denotes protected attributes or operations
• ~ denotes default (package only) attributes or operations

Parameter Directionality

• in
• inout
• out

Perspectives of Class Diagram

• Conceptual: represents the concepts in the domain
• Specification: focus is on the interfaces of Abstract Data Type (ADTs) in the software
• Implementation: describes how classes will implement their interfaces

Relationships between classes

• Generalization (Inheritance): Represents an “is-a” relationship.
• Realization: (Interface implemention) the reationship between blueprint and implemention
• Association: two classes have relationship
• Dependency: A special type of association, class is used in parameter but not stored as a member varible.
• Aggregation: A special type of association, represents a “part of” relationship. Two classes have separate lifetimes.
• Composition: A special type of aggregation where parts are destroyed when the whole is destroyed. (same lifetime)