java 中怎么用for循环写6！+5!+4!+3！+2！+1！

Question

java 中怎么用for循环写6！+5!+4!+3！+2！+1！也就是阶乘求和

Answer 1

int sum=0;
int num = 1;
for(int i=1;i<=6;i++)
{
for(int j=1;j<=i;j++)
{
num = num * j;
}
sum = sum +num;
}//求和的结果在sum里

Answer 2

package com.penol.arithmetic;
/**
*
* @author penol
*
*/
public class ForDemo {

/**
* desc:求阶乘
* @param n
* @return
*/
public static int getFactorial(int n){
int product = 1;
for(int i=0;i<n;i++){
product += product*i;
}
return product;
}
/**
*
* @param n
* @param m
* @return
*/
public static int getTotal(int n,int m){

assert n>0;
assert m>0;
assert n<m:"n必须小于m";
int total = 0;
for(int i=n;i<=m;i++){
total +=getFactorial(i);
}
return total;
}
public static void main(String[] args){
for(int i=0;i<=3;i++){
System.out.println(i+"的阶乘为："+getFactorial(i));
}

System.out.println(getTotal(0,3));

}

}

Answer 3

同意楼上的