遍历 List 的方法: 1. for 2. advanced for 3. Iterator 4. while 5. ListIterator List<E> list 1. for for (int i = 0; i < list.size(); i++) { E element = list.get(i); } 2. advanced for for (E element : list) { } 3. Iterator for (Iterator<E> iter = list.iterator(); iter.hasNext(); ) { E element = iter.next(); } 4. while while (i < list.size()) { E element = list.get(i); i++; } 5. ListIterator for (ListIterator<E> iterator = list.listIterator(); iterator.hasNext(); ) { E element = iterator.next(); }