GUIDED PRACTICE

Objects and responsibilities

Assign behavior to the object that owns the relevant state.

A AceYourInterviews editorial · 6 min study

6:00Self-guided practice timer

The timer resets when you leave this page. Save your design separately.

Your challenge

Model a parking facility with spots, tickets, and pricing policies.

Your design draft

Clarify assumptions, explain your approach, and test the difficult cases. Save your draft, then compare it with the study notes.

Self-review checklist

I clarified the requirements and constraints.I explained why the approach works.I considered failures, boundaries, and alternatives.I identified one improvement for my next attempt.

Self-guided practice. Automated AI feedback and code execution are not connected.