using System.Collections.Generic;
public static void Main()
for(int i = 1; i<=10; i++)
var allUser = Users.AllUser;
Console.WriteLine(string.Join(",", allUser.Select(x => x.Name)));
public static class Users
private static Dictionary<int,User> _users = new Dictionary<int, User>();
public static List<User> AllUser { get{ return _users.Select(x => x.Value).ToList(); }}
public static void Add(this User _user, int id)
if(_users.ContainsKey(id) == false)
this.Name = string.Format("My name is {0}",id);
public int Id {get; set;}
public string Name {get; set; }