I've been stuck on this for awhile now. I am trying to remove elements of a set if they make a set criteria. However when iterating when I try to remove the element it fails.
I get the java.util.ConcurrentModificationException
private static void smallerSet(Set<Map<String, Int>> set){ for (Map<String, Integer> map : set){ for (String String : map.keySet()){ if ( true){ set.remove(map); } else{ //System.out.println("test"); } } } } Any advice would be greatly appreciated.
You cannot remove elements from a Collection while iterating over it with the enhanced for loop.
You should use an explicit Iterator and remove with the Iterator's remove() method:
Iterator<Map<String, Integer>> iter = set.iterator(); while (iter.hasNext ()) { Map<String, Integer> map = iter.next(); for (String str : map.keySet()){ if (some condition) { iter.remove(); break; // you should probably break from the inner loop // after removing an element } else { //System.out.println("test"); } } } 