What is the performance of a HashSet in Java?

What is the performance of a HashSet in Java?

The performance of a HashSet in Java is generally very efficient. It offers average time complexity of O(1) for add, remove, and contains operations due to its underlying hash table implementation.

Are there any scenarios where HashSet might perform poorly?

Yes, HashSet can perform poorly if there are many hash collisions, which can lead to O(n) time complexity for operations in the worst case.

How does it compare to other collections like ArrayList or TreeSet?

HashSet is faster than ArrayList for search operations but does not maintain order like ArrayList. TreeSet, on the other hand, maintains sorted order but has a higher time complexity of O(log n) for basic operations.

What factors can affect the performance of a HashSet?

Factors include the initial capacity, load factor, and the quality of the hash function used. A poor hash function can lead to more collisions.