Mermaid Class Diagram
Model object-oriented systems with UML class diagrams. Design classes, attributes, methods, and relationships for your software architecture.
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Quick Syntax Reference
Key syntax elements for creating UML class diagrams.
Class DefinitionDefine class members
class User {
-id: Long
-name: String
+getName(): String
}InheritanceShow class hierarchy
Animal <|-- Dog
Animal <|-- Cat
Vehicle <|-- CarAssociationsRelationship types
User --> Order
Company "1" --> "many" Employee
Customer ..> AddressVisibilityAccess modifiers
+ public
- private
# protected
~ package/internalMultiplicityCardinality notation
"1" - exactly one
"*" - many
"0..1" - zero or one
"1..*" - one or moreAnnotationsSpecial class types
<<interface>>
<<abstract>>
<<service>>
<<enumeration>>Use Cases
Class diagrams are fundamental for object-oriented design and software architecture.
System Design
Design object-oriented software systems.
Code Documentation
Document existing codebase architecture.
Pattern Modeling
Illustrate design patterns and their implementation.
API Design
Model class hierarchies for libraries and APIs.
Database Mapping
Map OOP concepts to database schemas.
Team Communication
Communicate design decisions to stakeholders.