class Program
    {
        

        //虽然是公有字段，但方法中失效。
        public static int _number = 10;


        static void Main(string[] args)
        {
            
            int a = 3;
            int res = Test(a);
            Console.WriteLine(res);
           //  Console.WriteLine(_number);
            Console.ReadKey();
        }
        public static int Test(int a)
        {
            a = a + 5;
            return a;
          //   Console.WriteLine(_number);
        }


        public static void TestTwo()
        {
          // Console.WriteLine(_number);
        }
    }