using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

             List<Person> personList = new List<Person>();

            personList.Add(new Person { Age = 10, Name = "John" });

            personList.Add(new Person { Age = 15, Name = "Ann" });

            personList.Add(new Person { Age = 8, Name = "Kevin" });

            personList.Sort(); 

            foreach (var item in personList)

            {

                Console.WriteLine(item.Name + ":" + item.Age);

            }   

    }

    public class Person : IComparable<Person>

    {

        public int Age { get; set; }

        public string Name { get; set; }

        public int CompareTo(Person other)

        {

            return this.Age.CompareTo(other.Age);

        }

    }   

}