Question

I have a List of Lists in java (grails) and I am trying to find the elements that exist in each list within the list. Does anyone have a quick way to do this? Thank you!

Answer 1

If lists have unique elements you can do it like this (bu unique elements I understand that one element can be placed in few lists, but only once per list. Otherwise if first list contains [1,2,2,3] and other contain [x,2,y] as output you will see [2,2] not [2] )

List tmpList=new ArrayList<>(lists.get(0));
for(int i=1; i<lists.size(); i++)
    tmpList.retainAll(new ArrayList<>(lists.get(i)));
System.out.println(tmpList);