Stream 流之 count

一、方法概述

Stream 流提供 count 方法来统计其中的元素个数

二、案例

@Slf4j
public class StreamDemo {
    public static void main(String[] args) {
        List<Person> personList = Arrays.asList(
                new Person(1, "大毛", 30, 175),
                new Person(2, "二毛", 25, 170),
                new Person(3, "三毛", 25, 170),
                new Person(4, "小毛", 20, 163));
        
        // 获取 Stream 流
        Stream<Person> personStream = personList.stream();

        long count = personStream.count();
        log.info("流中元素的个数是: {}",count);
    }
}

三、测试结果