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Item 388 of 426 · Diagrams and modelling tools, 13 of 18
Class diagram
Diagram
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Definition
A visual representation of an object-oriented system: classes (name, attributes, methods) and the relationships between them.
Example: Person with Student and Parent inheriting from it.
Found in: syllabus, course specifications, 2025 HSC marking guidelines, sample exam and familiarisation guidelines, school notes.
Where you'll use it in the test
Syllabus area: Diagrams and tools.
Question types it can appear in
- Drawing: Draw a class diagram with inheritance (2025 Q22, sample Q24)
- Short answer: Define, outline or explain it and tie it to the scenario.
- Multiple choice: Pick the option that matches the definition or example.
Where it has appeared in the paper
The Software Engineering Project (Part A, B). Part letters follow each paper’s own layout.
Related past questions
- 2025 HSC Q22 (3 marks): Modelling tools The Software Engineering Project (Part A) · 3 marks
- Sample exam Q24 (4 marks): Modelling tools (class diagram) The Software Engineering Project (Part B) · 4 marks
How to use it
A model sentence
Diagram: “A visual representation of an object-oriented system: classes (name, attributes, methods) and the relationships between them.” Then apply it: Person with Student and Parent inheriting from it.
In a short answer, give the definition in your own words first, then tie it to the situation in the question. Do not copy the example above unless it fits the scenario.
Command words used with it
No linked question shows the command word for this term. Across the past drawing and short answer questions in this bank the words used most are: Explain, Outline, Describe, Compare, Classify, Analyse. Check the actual word in your question.
Go deeper
- Flashcard: Class diagram in Diagrams and Modelling Tools (Years 11 and 12) · study that set
- Memorise: Drawing rules: DFD, structure chart, storyboard, decision tree, class diagram, ERD
- Notes: Part 3. Where this has been examined (see ../../question_bank.md) (The Software Engineering Project (Year 12))
- Notes: Part 3. Where this has been examined (see ../../question_bank.md) (Pseudocode, flowcharts and diagram rules)
- Notes: Modelling tools: DFD, structure charts, storyboards, flowcharts, class diagrams (The Software Engineering Project (Year 12))
- Notes: Drawing rules: DFD, structure chart, storyboard, decision tree, class diagram, ERD (Pseudocode, flowcharts and diagram rules)
- Full term page: every question, note and marking comment for Class diagram
Check yourself
Describe or sketch “Class diagram”: what it shows, its parts and when you would use it.
Reveal the answer
A visual representation of an object-oriented system: classes (name, attributes, methods) and the relationships between them.
Example: Person with Student and Parent inheriting from it.
Could be tested as: Drawing, Short answer, Multiple choice.
Quick multiple choice
In a class diagram, a hollow-headed (triangle) arrow between two classes shows:
- Inheritance (generalisation): the subclass is a kind of the superclass
- A data store
- Ownership of a database table
- A loop
Show the answer
A
Inheritance represents an 'is-a' relationship, drawn from subclass to superclass with a hollow triangle head. 2025 Q22 required inheritance symbols and multiplicity.
Source: original (written for this study pack; not a NESA question). Open it in the multiple-choice bank.