Select method (Sysmte.Linq namespace) has an overload to return the loop index.

With calling this overload, the index of the loop can be get without a temporary variable.

C# code

var array = new[] { "A", "B", "C" };

foreach (var item in array.Select((v, i) => new { v, i }))
{
    Console.WriteLine("value = {0}, index = {1}", item.v, item.i);
}

Result

value = A, index = 0
value = B, index = 1
value = C, index = 2