Interview Bluff

[vam186]

Had fun interviewing a person with 4 yrs experience on Java. The guy was bluffing his way through nonsensically with total confidence. The I asked him a simple question. What will happed if you add a duplicate value to a hashset. He said it will throw a Exception.
I asked What exception..
He said DuplicateValueException or AlreadyExistsException :) ..
I went one to ask him the difference between the 2 ;)