Item 1: Use Properties Instead of Accessible Data Members(Effective C#)

　　You can specify different accessibility modifiers to the get and set accessors in a property in C#.

　　Indexers can be virtual or abstract; indexers can have separate access restrictions for setters and getters. You cannot create implicit indexers as you can with properties.

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 
 6 namespace EffectiveCSharpItem1
 7 {
 8     public class Person 
 9     {
10         private string name;
11         private List<string> friends = new List<string>();
12 
13         public string Name 
14         {
15             get 
16             {
17                 return name;
18             }
19             protected set 
20             {
21                 this.name = value;
22             }
23         }
24 
25         public override string ToString()
26         {
27              return this.name;
28         }
29 
30         public string this[int index] 
31         {
32             get { return friends[index]; }
33             set { friends[index] = value; }
34         }
35 
36         public Person(string name) 
37         {
38             this.Name = name;
39             friends.Add("Summer");
40         }
41     }
42 
43     class Program
44     {
45         static void Main(string[] args)
46         {
47             Person p = new Person("Ray");
48             Console.WriteLine(p.ToString());
49             Console.WriteLine(p[0]);
50 
51             Console.Read();
52         }
53     }
54 }