Collections · interview question
Which collection is the clearest fit for tracking distinct coupon codes that have already been applied?
Multiple choiceEasychapter-4-curatedpremiumcollectionsset-interface-and-hashset
Answer and explanation
Correct answer
A. A HashSet<String>
Why
A set models uniqueness directly. HashSet is a good default when you care about membership and duplicate prevention more than ordering.
Test yourself on Collections
A free test with instant, explained results. No account needed.
More Collections questions
- Given a List<String> catalog, which method call on an Iterator<String> allows safe removal of an item during iteration?
- If you need to ensure that elements are processed in the exact order they are added but also need occasional access to…
- Given an e-commerce application that requires frequent updates and lookups of product prices, which collection would…
- Which operation is most efficient for an ArrayList?
- What will happen if you try to access an index in an ArrayList that is out of bounds?
- You need to store product IDs and ensure no duplicates, with the ability to retrieve them in sorted order. Which…