using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(EstPalindrome("kayak"));

        Console.WriteLine(EstPalindrome("Cerfal"));

        Console.WriteLine(Reverse("Kayak"));

        Console.WriteLine(Reverse("Cerfal"));

    }

    // EXERCICE 1

    public static void Vowel(String Chaine)

    {

        bool presence=false;

        for (int i = 0 ; i <(Chaine.Length-1) ; i++)

        {

            if ( (Chaine[i]=='a') || (Chaine[i]=='e') || (Chaine[i]=='i') || (Chaine[i]=='o') || (Chaine[i]=='u') || (Chaine[i]=='y'))

            {

                presence=true;

            }

            else

            {

                presence=false;

            }

        }

        if (presence == true)

        {

            Console.WriteLine("La chaine contient au moins une voyelle");

        }

        else

        {

            Console.WriteLine("La chaine ne contient aucune voyelle");

        }

    }

    // EXERCICE 2

    public static void IncrDecrSum(ref int Var1,ref int Var2,ref int Var3)

    {

        Var1++;

        Var2--;

        Var3=Var1+Var2;

        Console.WriteLine(Var1);

        Console.WriteLine(Var2);

        Console.WriteLine(Var3);

    }

    public static string Concatener(string Chaine1, string Chaine2)

    {

        return Chaine1+Chaine2;

    }

    public static string Reverse(string Chaine)

    {

        string inverse="";

        for (int i = (Chaine.Length-1) ; i>-1 ; i--)

        {

            inverse=inverse+Chaine[i];

        }

        return inverse;

    }

    public static bool EstPalindrome(string Chaine)

    {

        return Chaine==Reverse(Chaine);

    }

    public static void Concat_email(string Nom, string Prenom, string Domaine, string Extension)

    {

        string email= Prenom+'.'+Nom+'@'+Domaine+'.'+Extension;

        Console.WriteLine(email);

    }

}

​

​