java8 stream流，list元素string转int,求和

public class Demo {public static void main(String[] args) {List<String> stringList = new ArrayList<>();stringList.add("1");stringList.add("5");stringList.add("3");stringList.add("2");i.

m0_59259076

7199人浏览 · 2022-01-05 15:24:20

m0_59259076 · 2022-01-05 15:24:20 发布

IntStream mapToInt(ToIntFunction<? super T> mapper);
LongStream mapToLong(ToLongFunction<? super T> mapper);
DoubleStream mapToDouble(ToDoubleFunction<? super T> mapper)

以上方法截自java8源码：package java.util.stream;

public class Demo {
    public static void main(String[] args) {
        List<String> stringList = new ArrayList<>();
        stringList.add("1");
        stringList.add("5");
        stringList.add("3");
        stringList.add("2");
        int sum = stringList.stream().mapToInt(Integer::parseInt).sum();
        System.out.println("sum = " + sum); // 控制台输出 sum = 11
    }
}