Java易错、易混淆（二）

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/x18094/article/details/89226924

1.Iterator 迭代，第2个循环输出什么？

	List<Integer> list = new ArrayList<>();
		list.add(1);
		list.add(2);
		list.add(3);
		Iterator<Integer> it = list.iterator();
		while(it.hasNext()){
			System.out.println(it.next());
		}
		while(it.hasNext()){
			System.out.println(it.next());
		}

 相关资料：

        public boolean hasNext() {
            return cursor != size;
        }

        @SuppressWarnings("unchecked")
        public E next() {
            checkForComodification();
            int i = cursor;
            if (i >= size)
                throw new NoSuchElementException();
            Object[] elementData = ArrayList.this.elementData;
            if (i >= elementData.length)
                throw new ConcurrentModificationException();
            cursor = i + 1;
            return (E) elementData[lastRet = i];
        }