3 ways to flatten a list of lists. Is there a reason to prefer one of them?

Question

Assume we have a list as follows. CoreResult has a field of type List.

final List list = new LinkedList         


        

Answer 1

I would go for option 2 or 3. If you want to flatten a List>, you would do this:

List list = doubleList.stream()
                              .flatMap(List::stream)
                              .collect(Collectors.toList());