namespace ConsoleApplication5
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Enter a string:");
            string myString = Console.ReadLine();
            string reversedString = "";
            for (int i = myString.Length - 1; i >= 0; i--)
            {
                reversedString += myString[i];
            }
            Console.WriteLine("Reversed: {0}", reversedString);
            Console.ReadKey();
        }
    }
}
红色一句中的 = "" 有什么用？谢谢