🧠 From Java Collections to Interview Readiness

Reading my last posts casually takes around 20–25 minutes.

But reading them as a developer trying to understand why each collection exists and how it maps to real systems takes much longer and that's where learning actually happens.

At this point, you're no longer just reading about List, Set, and Map.

You're training the kind of reasoning expected in technical interviews.

✅ Questions you should answer after reading the posts

1 - What real-world problem does each collection model: List, Set, and Map?

2 - Why is Set the right choice when uniqueness is a business rule, not just a technical detail?

3 - How do HashSet, LinkedHashSet, and TreeSet differ conceptually in terms of ordering?

4 - Why can choosing the wrong collection lead to bugs even when the code compiles?

🔍 Questions to explore next (require deeper study)

5 - How does HashSet enforce uniqueness internally when add() is called?

6 - Why is LinkedHashSet slower than HashSet, and what trade-off does it introduce?

7 - What happens when you insert a duplicate key into a Map? How is this different from inserting a duplicate element into a Set?

8 - Imagine a system that must:

Which collections would you choose, and why?

If you can answer the first four, you understood the core ideas. If you can answer most of these questions clearly, you're already thinking beyond syntax and into system modeling.

💬 Pick one question and answer it in the comments.

🔖 Save this post to revisit before your next interview.