Getting the difference between two sets

Question

So if I have two sets:

Set<Integer> test1 = new HashSet<Integer>();

test1.add(1);

test1.add(2);

test1.add(3);

Set<Integer> test2 = new HashSet<Integer>();

test2.add(1);

test2.add(2);

test2.add(3);

test2.add(4);

test2.add(5);

Is there a way to compare them and only have a set of 4 and 5 returned?

Answer 1

Try this

test2.removeAll(test1);

Set#removeAll

Removes from this set all of its elements that are contained in the specified collection (optional operation). If the specified collection is also a set, this operation effectively modifies this set so that its value is the asymmetric set difference of the two sets.