初学者习题练习。从控制台输入一个数n，使用for循环实现求n! 提示：n! =n*(n-1)*(n-2)*…*1 升级：求1！+2！+3!+…+n!的值

Posted 2021-02-19 ztzz

import java.util.*;

import com.sun.org.apache.xerces.internal.util.SynchronizedSymbolTable;

public class Demo13 {

public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int jc = 1; // 6!=1*2*3*4*5*6=720
int he = 0;
System.out.println("请输入n的值:");
int n = input.nextInt();
for (int i = 1; i <= n; i++) {
jc *= i; // 1*1=1 1*2=2 2*3=6 6*4=24 24*5=120 120*6=720
he += jc;

}
System.out.println(n + "的阶层是：" + jc);
System.out.println("1!+..." + n + "!的值是：" + he);

}

}