Core Java · interview question
In a large HashMap, what is a potential drawback of all keys having the same hashCode?
Multiple choiceMediumchapter-4-curatedpremiumcore-javaequals-and-hashcode-in-collections
Answer and explanation
Correct answer
D. Performance degrades to that of a linked list.
Why
If all keys have the same hashCode, they are stored in the same bucket, degrading performance to O(n) for operations, similar to a linked list. Hash-based collections rely on hashCode to evenly distribute entries.
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