Must-do problems: Composition and Relationships

150 min · Beginner

Back to syllabus (Composition & Relationships)

Every problem here asks you to design a few classes that work together: decide which object creates each part, who else may hold it, and which object does the work. Write the classes first, keep every part private, and run every test before opening a hint.

What you will learn

Choose association, aggregation or composition for each part
Keep two-way links and array-based parts consistent
Delegate work through an interface and swap it at run time
Protect owned parts with copies and data-only getters

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