输入整数n和m，1<=n<=m<=15输出n到m所有整数的乘积

输入整数n和m，1<=n<=m<=15输出n到m所有整数的乘积

package com.sofwin.controller;

import java.util.Scanner;

/**
 * @author : wentao
 * @version : 1.0
 */
public class Demo {
    public static void main(String[]args){
        Scanner sc=new Scanner(System.in);
       int n=0;
       int m=0;
       //判断n要大于等于1
      do {
          System.out.println("请输入整数n： (整数n要大于都等于1)");

           n = sc.nextInt();
      }while (n<1);
      //判断m要大于等于n  并且小于的能与15
        do {
            System.out.println("请输入整数m：  (m要大于等于n,并且小于的能与15)");
            m = sc.nextInt();
        }while (m>15||m<n);
        int sum=1;  //记录结果的数据
        //循环遍历得出结果
        for (int i=n;i<=m;i++){
            sum=sum*i;
        }
        System.out.print("结果为："+sum);


    }
}

import java.util.Scanner;
 public class Test{
public static void main(String args[]) {
int i, m, n,sum=1;
Scanner in = new Scanner(System.in);
n = in.nextInt();
m = in.nextInt();
for(i=n;i<=m;i++)
sum=sum*i;
System.out.println(sum);

}
}

参考下，
有用记得采纳

        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入a");
        int a = scanner.nextInt();
        System.out.println("请输入b");
        int b = scanner.nextInt();
        Integer integer = IntStream.range(a, b+1)
                .boxed().reduce((x, y) -> x * y).get();
        System.out.println("========= result: "+ integer);

public static void main(String[] args) {
    //输入整数n和m,1<=n<=m<=15输出n到m所有整数的乘积
    long sum = 1;
    int n = 0;
    int m = 0;
    Scanner scanner = new Scanner(System.in);
    System.out.println("请输入n的值");
    n = scanner.nextInt();
    System.out.println("请输入m的值");
    m = scanner.nextInt();
    if (!(n > 0 & n < m & m <16)){
        System.out.println("请输入1~15之间整数，并确保n<m");
    }else {
        for (int i = n; i <= m; i++) {
            sum *= i;
        }
        System.out.println("n~m之间整数乘积为：" + sum);
    }
}