Divide array into an array of subsequence array

Question

I have a byte array:

byte[] bytes;  // many elements

I need to divide it into subsequence of byte arrays of X elements. For example, x = 4.

If bytes.Length does not multiply by X, then add 0 to last subsequence array so Length of all subsequnce must be X.

Linq available.

PS: my attempts

static void Main(string[] args)
{
    List<byte> bytes = new List<byte>() { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };

    int c = bytes.Count / 4;

    for (int i = 0; i <= c; i+=4)
    {
        int diff = bytes.Count - 4;

        if (diff < 0)
        {

        }
        else
        {
            List<byte> b = bytes.GetRange(i, 4);
        }
    }

    Console.ReadKey();
}

Answer 1

Voted answer works if you always get source.Length % size != 0, though it is too verbose. Here goes a nicer implementation:

public static IEnumerable<T[]> AsChunks<T>(IEnumerable<T> source, int size)
{
    var chunk = new T[size];
    var i = 0;
    foreach(var e in source)
    {
        chunk[i++] = e;
        if (i==size)
        {
            yield return chunk;
            i=0;
        }
    }
    if (i>0) // Anything left?
    {
        Array.Resize(ref chunk, i);
        yield return chunk;
    }
}

void Main()
{
    foreach(var chunk in AsChunks("Hello World!",5))
        Console.WriteLine(new string(chunk));
}

Producing:

1. Hello
2. Worl
3. d!

Answer 2

This is quite cute:

static class ChunkExtension
{
    public static IEnumerable<T[]> Chunkify<T>(
        this IEnumerable<T> source, int size)
    {
        if (source == null) throw new ArgumentNullException("source");
        if (size < 1) throw new ArgumentOutOfRangeException("size");
        using (var iter = source.GetEnumerator())
        {
            while (iter.MoveNext())
            {
                var chunk = new T[size];
                chunk[0] = iter.Current;
                for (int i = 1; i < size && iter.MoveNext(); i++)
                {
                    chunk[i] = iter.Current;
                }
                yield return chunk;
            }
        }
    }
}
static class Program
{
    static void Main(string[] args)
    {
        List<byte> bytes = new List<byte>() {
              1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 };
        var chunks = bytes.Chunkify(4);
        foreach (byte[] chunk in chunks)
        {
            foreach (byte b in chunk) Console.Write(b.ToString("x2") + " ");
            Console.WriteLine();
        }
    }
}