using System;

using System.Linq;

using System.Collections.Generic;

​

public class Person

{

    public string Name {get;set;}

    public int Age {get;set;}

    public Person(string nm, int ag)

    {

        Name = nm;

        Age = ag;

    }

}

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        var col = new List<Person>();

        col.Add(new Person("Bob", 20));

        col.Add(new Person("Tim", 20));

        col.Add(new Person("Jim", 21));

        Console.WriteLine("All People:");

        col.Select(x=>x.Name).ToList().ForEach(Console.WriteLine);

        Console.WriteLine("Age 20 People:");

        col.Where(x=>x.Age == 20).ToList().ForEach(Console.WriteLine);

    }

}