using System;

using System.Collections.Generic;

using System.Linq;

​

class Program

{

    static void Main(string[] args)

    {

        DisplayDataFromFile();

    }

​

    private static void DisplayDataFromFile()

    {

        var people = PersonDataService.GetPeople().TakeWhile(p => p.LastName.Contains("s"));

        Console.WriteLine("PEOPLE READ FROM FILE:");

        foreach (var person in people)

        {

            Console.WriteLine($"First: {person.FirstName}");

            Console.WriteLine($"Last: {person.LastName}");

            Console.WriteLine($"Phone: {person.Phone}");

            Console.WriteLine($"Email: {person.EmailAddress}");

            Console.WriteLine(Environment.NewLine);

        }

    }

}

​

class PersonDataService

{

    public static List<PersonObj> GetPeople()

    {

        return new List<PersonObj>{new PersonObj{FirstName = "paul", LastName = "post", Phone = "(503) 393-3939", EmailAddress = "techmbabi@gmail.com"}, new PersonObj{FirstName = "mike", LastName = "sams", Phone = "(503) 434-3422", EmailAddress = "mike@gmail.com"}};

    }

}

​

public class PersonObj

{

    public string FirstName

    {

        get;

        set;

    }

​

    public string LastName

    {

        get;

        set;

    }

​

    public string Phone

    {

        get;

        set;

    }

​

    public string EmailAddress

    {

        get;

        set;

    }

}

​

public static class PersonHelper

{

    /// <summary>

    /// Return object from collection by name.

    /// </summary>

    /// <param name = "query"></param>

    /// <param name = "name"></param>

    /// <returns></returns>

    public static IEnumerable<PersonObj> ByName(this IEnumerable<PersonObj> query, string name)

    {

        return query.Where(p => p.FirstName == name);

    }

}