Class diagram maker examples.
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What a class diagram is.
A class diagram is a UML diagram of a system's static structure. It names the classes, their data and operations, then shows how the classes relate through inheritance, association, aggregation or composition.
Use it to decide which responsibilities belong together before implementation, or to explain an existing codebase. It describes the model rather than the order in which messages are sent at runtime.
- Standard
- OMG UML 2.5.1 §9–§11
- Also follows
- ISO/IEC 19505-2:2012 · Classification / Classifiers / Associations
- Engine
- schematex-umlclass
- Editable
- Double-click text, drag nodes
- Export
- SVG · PNG · PDF
Who uses a class diagram maker.
Class hierarchies and design patterns documented before implementation or during a design review.
A shared view of boundaries and dependencies when a team is planning a new service or module.
Small object-oriented examples that make attributes, methods and relationships easier to discuss.
How to make a class diagram in three steps.
Describe it
One paragraph is enough to start.
See the drawing
Drawn by the right engine.
Say what changes
Every edit keeps a version.
Common questions
What is a class diagram?
A class diagram is a UML diagram that shows the structure of a system through its classes, attributes, methods and relationships. It is commonly used to model object-oriented software.
What should I include in a class diagram?
Include the classes that matter to the design, their key attributes and operations, and the relationships between them. Add multiplicities when the number of related objects matters.
What is the difference between inheritance, composition and association?
Inheritance means a child class extends a parent class. Composition means one object owns another object's lifecycle. Association is a looser link in which both objects can exist independently.
What do the +, - and # symbols mean?
They show visibility in UML: + is public, - is private and # is protected. A public member is available outside the class, while private and protected members have narrower access.
How do I make a class diagram?
Describe the important classes, what each stores or does, and how they connect. For example, say which class owns another, which classes inherit, and whether a relationship is one-to-one or one-to-many.
Other drawings for the same work.
Make your first class diagram.
Free account, no card. Describe the classes and relationships you want to model.
Open the editor