C#用遞歸求階乘 n！

C#用遞歸方式求階乘

using System; using System.Collections.Generic; using System.Linq; using System.Text;  namespace 弟子規 {     class Program     {         public static double recursion(int n)         {                 return (n==1?1:n * recursion(n - 1));          }         static void Main(string[] args)         {             Console.Write(recursion(6));          }     } }

(假設n爲正整數)