public class LambdaTest {

    public static void main(String[] args) {

        // 相当于foreach遍历操作结果值

        Integer out = Stream.of(10, 5, 3, 2, 1, 0).reduce((result, item) -> {

            if (item >= 3) {

                result = result + item;

            }

            return result;

        }).get();

        System.out.println(out);

        // 相当于给定初始结果值，foreach遍历操作结果值

        Integer sum = Stream.of(10, 5, 3, 2, 1, 0).reduce(9, LambdaTest::sumTest);

        System.out.println(sum);

        //相当于给定初始结果值，两个foreach遍历操作结果值

        int str = Stream.of(1,2,3).parallel().reduce(1, (result, item) -> {

            return result + item;

        } , (result, item) -> {

            //注：只有并行parallel下才会进入此方法

            return result + item ;

        });

        System.out.println(str);

    }

    //替换Integer::sum测试

    public static Integer sumTest(int a1, int a2) {

        return a1 + a2;

    }

}