Collection of X elements, want to traverse them in groups of two (using Linq?)

Question

I have a collection of say 8 elements. I want to traverse it in such a way, that after 2 iterations I do something else, and then back to traversing.

A practical application is making a layout. I lay two square boxes, then I print a new line, and then I lay two square boxes.

is there a way I can make a sequence collection into something like this using Linq? Maybe using the Group by clause? Can't think of a solution though.

Collection --> "1, 2, 3, 4, 5, 6, 7, 8"

Want to print like

1 2

3 4

5 6

7 8

Answer 1

could you do something that uses skip and take

collection.Take(2) - takes first 2 elements
collection.Skip(2).Take(2) - skips first 2 and takes elements 3 and 4 

etc

i am not sure of the code that you have but im sure this may help if you can use it

Answer 2

Use an extension method such as the following:

public static IEnumerable<Tuple<TElement, TElement>> AsPairs<TElement>(this IEnumerable<TElement> @this)
{
    IEnumerator<TElement> enumerator = @this.GetEnumerator();

    while (enumerator.MoveNext())
    {
        TElement left = enumerator.Current;

        if (enumerator.MoveNext())
        {
            TElement right = enumerator.Current;

            yield return Tuple.Create(left, right);
        }
        else
        {
            throw new ArgumentException("this", "Expected an even number of elements.");
        }
    }
}

...
foreach (Tuple<TextBox, TextBox> pair = textBoxes.AsPairs())
{
    ...
}

Edit: Added exception in uneven enumerable case.

Answer 3

Here's your solution

    private static void TraverseInTwos()
    {
        var col = new Collection<int> { 1, 2, 3, 4, 5, 6, 7, 8 };
        int i = 0;
        while (col.Skip(i).Any())
        {
            var newCol = col.Skip(i).Take(2);
            Console.WriteLine(newCol.First() + " " + ((newCol.Count() > 1) ? newCol.Last().ToString() : string.Empty));
            i += 2;
        }
    }

Answer 4

Here you go :)

var ten = Enumerable.Range(20, 10);
var pairs = ten.Select((i,index) => new { group = (index >> 1), val = i }).GroupBy(a => a.group);

foreach (var pair in pairs)
{
    foreach (var i in pair) Console.Write(i.val + " ");
    Console.WriteLine();
}

/Moberg