Why the order of elements in HashSet's keySet changes from run to run?

Question

I have some code utilizing standard Java collections: arrays, ArrayDeques, HashMaps, Lists, HashSets. My code is expected to be deterministic: the hash codes of all the elem

Answer 1

From the documentation of HashSet:

It makes no guarantees as to the iteration order of the set; in particular, it does not guarantee that the order will remain constant over time.