static void Main(string[] args)

        {

            // C# 输出6*6 的矩形

            for (int i = 0; i < 6; i++)

            {

                for (int j = 0; j < 6; j++)

                {

                    if (i == 0 || i == 5)

                    {

                        Console.Write(" *");

                    }

                    else

                    {

                        if (j == 0 || j == 5)

                        {

                            Console.Write(" *");

                        }else

                        {

                            Console.Write("  ");

                        }

                    }

                }

                Console.Write("\r\n");

            }

            Console.ReadLine();

        }