下面程序运行的结果是() class A { public string[] list = new string[10]; public int this[int index] { get { return Convert.ToInt32(list[index]); } set { list[index] = value.ToString(); } } public Hashtable list1 = new Hashtable(); public int this[string name] { get { return (int)list1[name]; } set { list1[name] = value; } } } class Program { static void Main(string[] args) { A a = new A(); a["张三"] = 10; Console.WriteLine(a["张三"]); a[1] = 20; Console.WriteLine(a[1]); Console.ReadKey(); } }