Something like 'contains any' for Java set?

Question

I have two sets, A and B, of the same type.

I have to find if A contains any element from the set B.

What would be the best way to do that without iterating

Answer 1

There's a bit rough method to do that. If and only if the A set contains some B's element than the call

A.removeAll(B)

will modify the A set. In this situation removeAll will return true (As stated at removeAll docs). But probably you don't want to modify the A set so you may think to act on a copy, like this way:

new HashSet(A).removeAll(B)

and the returning value will be true if the sets are not distinct, that is they have non-empty intersection.

Also see Apache Commons Collections