ordering a hashset example?

Question

I need an example on how to use a comparable class on a HashSet to get an ascending order. Let’s say I have a HashSet like this one:

Answer 1

HashSets do not guarantee iteration order:

This class implements the Set interface, backed by a hash table (actually a HashMap instance). 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. This class permits the null element.

You probably need to choose a different datastructure if you want to be able to control the iteration order (or indeed have one at all!)