How to convert simple array to an array of consecutive pairs of its elements using LINQ?

Question

What is the easiest way to convert [a, b, c, d] to an array of consecutive pairs of its elements using LINQ [[a, b], [c, d]] ? Is it possible at all?

x = [a, b, c, d] → y = [[a, b], [c, d]]

P.S. If not LINQ then how it can be done in a simplest and efficient way?

So you want to pair even and odd elements from the original array? — wbennett, Jul 02 '14 at 13:30
[MoreLinq](https://code.google.com/p/morelinq/source/browse/MoreLinq/Batch.cs) features a `Batch` method that can do this. — Adam Houldsworth, Jul 02 '14 at 13:32
@Dennis_E It is not important. a,b,c,d can be any integer number. — NoWar, Jul 02 '14 at 13:33
Order doesn't matter? And yes, as @Dennis_E stated, to have everything paired you would need an even quantity. — wbennett, Jul 02 '14 at 13:35
@ClarkKent What I meant was: what should happen if you have for example [a,b,c,d,e] What should happen with e? But now I guess the array will always contain an even number of items. — Dennis_E, Jul 02 '14 at 13:36
var pairs = Enumerable.Range(0, array.Length / 2).Select(index => Tuple.Create(array[index * 2], array[index * 2 + 1]).ToArray(); — Dennis_E, Jul 02 '14 at 13:40

score 4 · Accepted Answer · answered Jul 02 '14 at 13:35

4

Yes it is possible, :

var result = yourCollection
             .Select((x,idx) => new { x, idx })
             .GroupBy(g => g.idx / 2)
             .Select(g => g.Select(p => p.x).ToArray())
             .ToArray();

Since there is no built-in method to do this directly, the code looks like messy.It would be better if you can use Batch method from MoreLINQ library.Then you can just use:

var result = yourCollection.Batch(2).Select(x => x.ToArray()).ToArray();

answered Jul 02 '14 at 13:35

Selman Genç

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That's awesome and working solution! I appreciate time you spent and your knowledge, man! Thank you very much! – NoWar Jul 02 '14 at 13:43

How to convert simple array to an array of consecutive pairs of its elements using LINQ?

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