递归实现阶乘

    class PRogram

    {

        static void Main(string[] args)

        {

            Console.WriteLine("请输入一个数");

            int number = Convert.ToInt32(Console.ReadLine());

            double result = JieCheng(number);

            Console.WriteLine(number.ToString() + "的阶乘结果是：" + result.ToString());

            Console.ReadKey();

        }

        public static double JieCheng(int number)

        {

            if (number == 0)

            {

                return 0;

            }

            //初始值必须设置为1

            double result = 1;

            for (int i = number; i >= 1; i--)

            {

                result = result*i;

            }

            return result;

        }

    }