jdk1.8 新特性之 forEach 循环遍历

1、Foreach操作List

1. List<Integer> numbers = new ArrayList<>();

2.  

3. //no.1

4. for(Integer number : numbers){

5. System.out.println(number);

6. }

7.  

8. //no.2

9. for(int index=0,len=numbers.size();index<len;index++){

10. System.out.println(numbers.get(index));

11. }

使用jdk1.8后，可这么写

1. //no.1

2. numbers.forEach((Integer integer) -> {

3. System.out.println(integer);

4. });

5.  

6. //no.2

7. numbers.forEach(integer -> {

8. System.out.println(integer);

9. });

10.  

11. //no.3

12. numbers.forEach(integer -> System.out.println(integer));

13.  

14. //no.4

15. numbers.forEach(System.out::println);

16.  

17. //no.5

18. numbers.forEach(new MyConsumer());

2、 Foreach操作Map