Set by Default Sorted or Not?

Question

UPDATED:

    Set s = new HashSet();
    s.add(1);
    s.add(5);
    s.add(4);
    s.add(9);
    s.add(7);
    s.add(8);        
    s.add(\"         


        

Answer 1

No, HashSet is not sorted - or at least, not reliably. You may happen to get ordering in some situations, but you must not rely on it. For example, it's possible that it will always return the entries sorted by "hash code modulo some prime" - but it's not guaranteed, and it's almost certainly not useful anyway.

If you need a sorted set implementation, look at TreeSet.