Java · Junior · Theory

What is the equals and hashCode contract, and what happens if you break it?

~4 min by voice

How to approach it

They're checking whether the candidate understands how equals and hashCode are linked and why hash collections (HashMap, HashSet) depend on that link. Not just "I generate them in the IDE", but what exactly breaks when the contract is violated, and why.

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Topics

equals hashcode collections

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Answer by voice

The interviewer will ask this question and listen. Think out loud and ask for a hint if you need one. When you're done, pause or tap “That's my answer”. In about a minute, your score and the points you covered show up here.

Best with headphones · ~4 min