In what order Set items are sorted when converting to Array

Question

I'm interested in what criteria are used to sort Set when converting? And how can this be overridden? Because, as I understand it, Set does not store sorting information. An example of the conversion I'm talking about:

    Set<Object> objectsSet = new HashSet<>();
    Objects[] objectsArray = (Objects[]) objectsSet.toArray();

Answer 1

Not sorted. LinkedHashSet preserves insertion order; HashSet is going to be ordered by the hashCode() internally. If you want a sorted Set, use a TreeSet (which implements SortedSet).

SortedSet<Object> objectsSet = new TreeSet<>();
Objects[] objectsArray = (Objects[]) objectsSet.toArray();

As for changing the order (ascending or descending), you can use TreeSet(Comparator<? super E> comparator) when constructing the Set. For example, to sort integers in reverse order;

SortedSet<Integer> intSet = new TreeSet<>(Comparator.reverseOrder());