using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Person[] people = new Person[]

        {

            new Person { FirstName = "Hubert", LastName = "Cumberdale" },

            new Person { FirstName = "Marjorie Stewart", LastName = "Baxter" }

        };

        foreach(var person in people)

        {

            Console.WriteLine( person.GetHashCode() );

        }

        var somePeople = people.Where(p => p.FirstName.Length > 0);

        Console.WriteLine();

        foreach(var person in somePeople)

        {

            Console.WriteLine( person.GetHashCode() );

        }

​

        var peeps = somePeople.ToList();

        Console.WriteLine();

        foreach(var person in peeps)

        {

            Console.WriteLine( person.GetHashCode() );

        }

    }

}

​

​

​

class Person

{

    public string FirstName { get; set; }   

    public string LastName { get; set; }

}

​