How to Iterate through two ArrayLists Simultaneously? [duplicate]

Answer 1

If you do this often you may consider using a helper function to zip two lists into one pair list:

public static  List> zip(List listA, List listB) {
    if (listA.size() != listB.size()) {
        throw new IllegalArgumentException("Lists must have same size");
    }

    List> pairList = new LinkedList<>();

    for (int index = 0; index < listA.size(); index++) {
        pairList.add(Pair.of(listA.get(index), listB.get(index)));
    }
    return pairList;
}

You will also need a Pair implementation. Apache commons lang package has a proper one.

And with these you can now elegantly iterate on the pairlist:

ArrayList category = new ArrayList();
ArrayList cat_ids = new ArrayList();

for (Pair item : zip(category , cat_ids)) {
   // do something with JRadioButton
   item.getLeft()...
   // do something with Integer
   item.getRight()...
}