for

    private static void traversalList() {
        List<String> list = new ArrayList<String>();
        list.add("aa");
        list.add("bb");
        list.add("cc");
        list.add("dd");
        list.add("ee");
        for (int i = 0; i < list.size(); i++) {
            System.out.println(list.get(i));
        }
        for (String l : list) {
            System.out.println(l);
        }
        Iterator<String> iterator = list.iterator();
        while(iterator.hasNext()){
//          iterator.next();
            System.out.println(iterator.next());
        }
    }