How to iterate through two collections of the same length using a single foreach

This is possible using .NET 4 LINQ Zip() operator or using open source MoreLINQ library which provides Zip() operator as well so you can use it in more earlier .NET versions

Example from MSDN:

int[] numbers = { 1, 2, 3, 4 };
string[] words = { "one", "two", "three" };

// The following example concatenates corresponding elements of the
// two input sequences.
var numbersAndWords = numbers.Zip(words, (first, second) => first + " " + second);
foreach (var item in numbersAndWords)
{
    Console.WriteLine(item);
}

// OUTPUT:
// 1 one
// 2 two
// 3 three

Useful links:

• Soure code of the MoreLINQ Zip() implementation: MoreLINQ Zip.cs