int N = 2345;
        var digitArray = N.ToString().ToCharArray();
        int multiplicationSum = 1;
        foreach (char digit in digitArray)
        {
            multiplicationSum = int.Parse(digit.ToString()) * multiplicationSum;
        }
        var sum = 0;
        var sumArray = multiplicationSum.ToString().ToCharArray();
        foreach (char digit in sumArray)
        {
            sum = int.Parse(digit.ToString()) + sum;
        }

感谢

推荐答案

假设你不需要处理负数，好像做数学会赚很多更有意义

Assuming you don't need to deal with negative numbers, it seems doing it mathematically would make a lot more sense

int N = 2345;
int multiplicationSum = 1;
while(N!=0)
{
  multiplicationSum = multiplicationSum * (N%10);
  N = N/10;
}
var sum = 0;
while(multiplicationSum!=0)
{
  sum = sum + (multiplicationSum%10);
  multiplicationSum = multiplicationSum/10;
}

参考文献：

References:

％运营商

％运算的第一个操作数由第二分割计算后的余

The % operator computes the remainder after dividing its first operand by its second

/运营商：

当你把两个整数，结果始终是一个整数。例如，7/3的结果是2

When you divide two integers, the result is always an integer. For example, the result of 7 / 3 is 2