多重迴圈中的break，continue的使用

public static void main(String[] args) {

        List<Integer> list1 = Arrays.asList(1,2,3,4,5);
        List<String> list2 = Arrays.asList("a","b","c","d");
        a:
        for (Integer a :list1){
            System.out.println(a);
            for(String b:list2){
                System.out.println(b);
                break;--跳出內部for迴圈
//                break a;--跳出外部for迴圈
                continue a;--調出外部迴圈，執行下次外部迴圈
            }
        }
    }