Remove all objects in an arraylist that exist in another arraylist Java
ArrayList<String> firstArr = new ArrayList<>(); firstArr.add("1"); firstArr.add("2"); firstArr.add("3"); // array/list to be removed from firstArr ArrayList<String> filterArr = new ArrayList<>(); filterArr.add("1"); filterArr.add("3"); // filter now filterArr.removeAll(blockedArr); // Dump System.out.println(filterArr.toString); // output 1 and 3