ConcurrentModificationException when using iterator and iterator.remove()

Question

    private int checkLevel(String bigWord, Collection dict, MinMax minMax)
{
    /*value initialised to losing*/
    int value = 0; 
    if (minMax ==          


        

Answer 1

You can't modify a Collection while you're iterating over it with an Iterator.

Your attempt to call iter.remove() breaks this rule (your removeWord method might, too).

You CAN modify a List while iterating IF you use a ListIterator to iterate.

You can convert your Set to a List and use a List iterator:

List tempList = new ArrayList(dict);
ListIterator li = tempList.listIterator();

---

Another option is to keep track of the elements you want to remove while iterating.

You could place them in a Set, for example.

You could then call dict.removeAll() after your loop.

Example:

Set removeSet = new HashSet();
for (String s : dict) {
    if (shouldRemove(s)) {
        removeSet.add(s);
    }
}
dict.removeAll(removeSet);