using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Implementing IEnumerable ....");

        List<double> Notes = new List<double>();

        Notes.Add(7.5);

        Notes.Add(8.5);

        Notes.Add(10);

        Notes.Add(9);

        Notes.Add(4);

        /************************************************************************************************************************

        * The Sum method described here does not exist on either the array abstract base class or the List type.                *

        * It is instead an extension method found in the System.Linq namespace, which you must include with a using directive.  *

        *************************************************************************************************************************/

        double sumNotes = Notes.Sum();

        Console.WriteLine(" Somme = " + sumNotes);

        Player s1 = new Player();

        s1.FirstName = "hakim";

        s1.lastName = "Ziyech";

        s1.Notes.Add(3.5); // runtime ereur si l'objet list n'est pas instancié, voir commentaire dans ctor class Student

        s1.Notes.Add(4);

        s1.Notes.Add(5);

        Console.WriteLine("Moyenne : " + s1.Notes.Average());

        s1.viewNotes(s1.Notes);

        Console.WriteLine();

        Console.WriteLine();            

        // When you create your own class, you may want an easy way to cycle though the data within the class.

        // On souhaiterai pouvoir utilisé un foreach pour parcourir la liste de notes de notre joueur.

        // Mais on obtient cette erreur :

        // [ foreach statement cannot operate on variables of type 'Player' because 'Player' does not contain a public definition for 'GetEnumerator']

        foreach (double val in s1)

        {

            Console.WriteLine("Implementing IEnumerable for the Class Player ....******* "  + val);

        }

        s1.Tab[0] = 10;

        s1.Tab[1] = 20;

        s1.Tab[2] = 30;

        /*foreach (int val in s1)

        {

            Console.WriteLine("Implementing IEnumerable for the Class Player ....******* "  + val);

        }*/

    }

}

​

public class Player : IEnumerable // Visiblement, implement l'interface IEnumerable n'est pas MANDATORY

{

    public string FirstName {get; set;}

    public string lastName {get; set;}

    public List<double> Notes {get; set;}

    public int[] Tab {get; set; }

    public Player()

    {

        // Ligne indispensable, 

        //sinon obtient l'erreur suivante : "Object reference not set to an instance of an object."

        // c-a-d notre variable list est crée mais pas instancié.

        Notes = new List<double>(); 

        Tab = new int[3];

    }

    public void viewNotes(List<double> list)

    {

        foreach(var item in list)

        {

            Console.Write(item + " ** ");

        }

    }

    /*

    public IEnumerator GetEnumerator()

    {

        foreach (double item in Notes)

        {

            yield return item;

        }

    }

    */

    public IEnumerator GetEnumerator()

    {

        foreach (double item in Notes)

        {

            yield return item;

        }

    }

}

​

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