Java Stream流之求和
package top.yangbocsu;
import java.util.Arrays;
/**
* @author yangbocsu
* @date 2022年4月14日
* @version 1.0
* @description: 流方式实现 基本数据类型 和 包装类型 的一位数组求和
*/
public class Test {
public static void main(String[] args) {
// 基本数据类型 int long double
int[] arr2 = new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
int sum2 = Arrays.stream(arr2).sum();
long[] arr3 = new long[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
long sum3 = Arrays.stream(arr3).sum();
double[] arr5 = new double[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
double sum5 = Arrays.stream(arr5).sum();
// 包装类型 Integer Long Double
Integer[] arr4 = new Integer[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
Integer sum4 = Arrays.stream(arr4).mapToInt(Integer::intValue).sum();
Long[] arr6 = new Long[]{1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 10L};
Long sum6 = Arrays.stream(arr6).mapToLong(Long::longValue).sum();
Double[] arr7 = new Double[]{1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0};
Double sum7 = Arrays.stream(arr7).mapToDouble(Double::doubleValue).sum();
System.out.println("sum2 = " + sum2);
System.out.println("sum3 = " + sum3);
System.out.println("sum4 = " + sum4);
System.out.println("sum5 = " + sum5);
System.out.println("sum6 = " + sum6);
System.out.println("sum7 = " + sum7);
}
}