using System;

using System.Collections.Generic;

public interface IPerson

{

    //the first name are just property that each thing that has IPerson

    string firstName{get; set;}

    string lastName{get; set;}

}

​

public class Person

    : IPerson

{

    public string firstName{get; set;}

    public string lastName{get; set;}

}

public void ShowPerson(IPerson p)

    {

             Console.WriteLine(p.firstName + " " + p.lastName);

    }

var p = new Person{ firstName = "Dave", lastName = "Suheil"};

ShowPerson(p);

public class Student

    : IPerson

{

    public string firstName{get; set;}

    //string IPerson.firstName{get; set;}

    public string lastName{get; set;}

    //string IPerson.lastName{get; set;}

    public string StudentID{get; set;}

}

var s = new Student {firstName = "Sami", lastName = "Suheil" , StudentID = "1"};

//IPerson s = new Student {StudentID = "1" };

//s.firstName = "Sami";

//if you dont start it with IPerson because firstName is explicit now.

//((IPerson)s).FirstName = "Sami";

//s.lastName = "Mustaklem";

​

ShowPerson(s);

​

​

​

​

IEnumerable<int> c = new List<int> {1, 2, 3, 4, 5};

//ienumerable help go through the list

​

//var e = c.GetEnumerator();

​

//while (e.MoveNext())

//{

    //Console.WriteLine(e.Current);

//}

//or

foreach (var e in c)

{

    Console.WriteLine(e);

}

​

​

​