1 class Program
 2 {
 3     static void Main(string[] args)
 4     {
 5         List<Person> personList = new List<Person>()
 6         {
 7             new Person(){Name="Rose",Age=18},
 8             new Person(){Name="Mike",Age=25},
 9             new Person(){Name="john",Age=18}
10         };
11         var items = from p in personList
12                     select new { p.Name, AgeScope = p.Age > 20 ? "Old" : "Young" };
13         foreach (var item in items)
14         {
15             Console.WriteLine(string.Format("{0}:{1}", item.Name, item.AgeScope));
16         }
17         Console.Read();
18     }
19 }
20 class Person
21 {
22     public string Name { get; set; }
23     public int Age { get; set; }
24 }