using System;

using System.Collections.Generic;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        var people = new List<Person>()

        {

            new Person("Bill", "Smith", 41),

            new Person("Sarah", "Jones", 22),

            new Person("Stacy","Baker", 21),

            new Person("Vivianne","Dexter", 19 ),

            new Person("Bob","Smith", 49 ),

            new Person("Brett","Baker", 51 ),

            new Person("Mark","Parker", 19),

            new Person("Alice","Thompson", 18),

            new Person("Evelyn","Thompson", 58 ),

            new Person("Mort","Martin", 58),

            new Person("Eugene","deLauter", 84 ),

            new Person("Gail","Dawson", 19 ),

        };

        //write linq statement for people with last name that starts with the letter D

        var people1 = from person in people

                      where person.LastName.StartsWith("D") // || person.LastName.StartsWith("d")

                      select person;

        Console.WriteLine("Number of people who's last name starts with the letter D " + people1.Count());

        //Write linq statement for first Person Older Than 40 In Descending Alphabetical Order By First Name

        var person2 = (from person in people 

                      where person.Age > 40

                      orderby person.FirstName ascending

                      select person).First();

        Console.WriteLine("First Person Older Than 40 in Descending Order by First Name " + person2.ToString());

    }

    public class Person

    {

        public Person(string firstName, string lastName, int age)

        {

            FirstName = firstName;

            LastName = lastName;

            Age = age;

        }

        public string FirstName {get;set;}

        public string LastName {get;set;}

        public int Age {get;set;}

        //override ToString to return the person's FirstName LastName Age

        public override string ToString()

        {

            return this.FirstName + " " + this.LastName + " " + this.Age;

        }

    }

}