package com.mayikt.stream; import java.util.Optional; import java.util.function.BinaryOperator; import java.util.stream.Stream; /** * @ClassName Test10 * @Author 螞蟻課堂余勝軍 QQ644064779 www.mayikt.com * @Version V1.0 **/ public class Test10 { public static void main(String[] args) { StreamintegerStream = Stream.of(10, 20, 30); Optional reduce = integerStream.reduce(new BinaryOperator () { @Override public Integer apply(Integer a1, Integer a2) { return a1 + a2; } }); System.out.println(reduce.get()); } }