public class Fruit {         string peach = "a round juicy fruit that has a soft yellow or red skin and a large hard seed in the center, or the tree that this fruit grows on";         string orange = "a round fruit that has a thick orange skin and is divided into parts inside";         string banana = "a long curved tropical fruit with a yellow skin";         string apple = "a hard round fruit that has red, light green, or yellow skin and is white inside ";         public string this[string fruitName]         {             get             {                 switch (fruitName)                 {                     case "peach":                         return peach;                     case "orange":                         return orange;                     case "banana":                         return banana;                     case "apple":                         return apple;                     default:                         throw new Exception("wrong fruit name");                 }             }             set             {                 switch (fruitName)                 {                     case "peach":                         peach = value;                         break;                     case "orange":                         orange = value;                         break;                     case "banana":                         banana = value;                         break;                     case "apple":                         apple = value;                         break;                     default:                         throw new Exception("wrong fruit name");                 }             }         }     }     class Program     {         static void Main(string[] args)         {             Fruit f = new Fruit();             //关联数组的方式访问get方法             Console.WriteLine(f["peach"]);             //关联数组的方式访问set方法             f["peach"] = "I like to eat peach.";             Console.WriteLine(f["peach"]);             Console.ReadLine();         }     }