What is the difference between hashset and treeset

Question

When to use hashset and when to use treeset?

Answer 1

HashSet vs TreeSet:

1- Hashset gives better performance (faster) than Treeset for the operations like add, remove, contains, size etc. HashSet offers constant time cost while TreeSet offers log(n) time cost for such operations.

2- HashSet does not maintain any order of elements while TreeSet elements are sorted in ascending order by default.

Similarities:

1-  Both HashSet and TreeSet does not hold duplicate elements, which means both of these are duplicate free.

2- If you want a sorted Set then it is better to add elements to HashSet and then convert it into treeset rather than creating a TreeSet and adding elements to it.