JAVA8学习(一)List、Map的循环迭代

学习怎样用java8去循环迭代

1、Map

Map<Integer, String> items = new HashMap<>();items.put(1, "wangwu");items.put(2, "zhangsan");items.put(3, "lisi");items.forEach((k,v)->System.out.println("Item : " + k + " Count : " + v));items.forEach((k,v)->{System.out.println("Item : " + k + " Count : " + v);if("zhansan".equals(k)){System.out.println("Hello zhangsan");}});

2、List

List<String> items = new ArrayList<>();items.add("A");items.add("B");items.add("C");items.add("D");items.add("E");//lambda//Output : A,B,C,D,Eitems.forEach(item->System.out.println(item));//Output : Citems.forEach(item->{if("C".equals(item)){System.out.println(item);}});//method reference//Output : A,B,C,D,Eitems.forEach(System.out::println);//Stream and filter//Output : Bitems.stream().filter(s->s.contains("B")).forEach(System.out::println);