Collections · interview question
Why must Product implement consistent equals and hashCode before being stored in a HashSet?
Multiple choiceMediumchapter-4-curatedpremiumcollectionsequals-and-hashcode-in-collections
Answer and explanation
Correct answer
B. So uniqueness and lookup are based on the domain identity the model intends
Why
Hash-based collections depend on equals and hashCode to decide sameness and bucket placement. If domain identity is SKU, those methods must reflect that rule for duplicate prevention and key lookup to work correctly.
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