using System;

using System.Collections.Generic;

using System.Linq;

​

public static class LINQextra

{

    public static void ForEach<T>(this IEnumerable<T> enumerable, Action<T, int> action)

    {

        var max = enumerable.Count();

        for(var index = 0; index < max; index++)

        {

            T current = enumerable.ElementAt(index);

            action(current, index);

        }

    }

}

​

public class Program

{

    public static void Main()

    {

        var listaString = new[] { "A", "B", "C", "D", "E" };

        listaString.ForEach((x, i) => Console.WriteLine(x + " - " + i));

    }

}