How to calculate the intersection of two sets?

Question

Say, have two Hashset, how to calculate the intersection of them?

Set<String> s1 = new HashSet<String>();

Set<String> s2 = new HashSet<String>();

S1 INT S2 ?

Answer 1

Yes there is retainAll check out this

Set<Type> intersection = new HashSet<Type>(s1);

intersection.retainAll(s2);