Found this code on this link java.sun. What I would like explaining is the logic in the if statement I have commented. I am not that familier with all the different collection interfaces & classes. Thanks, Dave.
The TreeSet's add method returns true if the addition was succesful. As the TreeSet, like all Sets, doesn't allow duplicates it will return false when trying to add a String that already exists in the Set. Don't know if this helps, but another way to present this would be like this:
Mika Leino<br />SCJP, SCWCD
Joined: May 25, 2003
Thanks Mika, I can see the logic clearly now, your'a'good'un!
TreeSet implements Set which defines add(), addAll(), remove(), removeAll() and retainAll(), all of which return boolean. Each of these adds or removes objects to/from the set. But adding/removing may turn out to be a no-op (because the specified object is/is-not in the set). So each of these methods returns a boolean which says "I changed the set".