I want to merge down 3 arraylist in one in java. Does anyone know which is the best way to do such a thing?
ArrayList.addAll(). Something like this should work (assuming lists contain
String objects; you should change accordingly).
List<String> combined = new ArrayList<String>(); combined.addAll(firstArrayList); combined.addAll(secondArrayList); combined.addAll(thirdArrayList);
I can see by your comments that you may actually be trying to create a 2D list. If so, code such as the following should work:
List<List<String>> combined2d = new ArrayList<List<String>>(); combined2d.add(firstArrayList); combined2d.add(secondArrayList); combined2d.add(thirdArrayList);