Split string in 512 char chunks

Question

Maybe a basic question but let us say I have a string that is 2000 characters long, I need to split this string into max 512 character chunks each.

Is there a nice way, like a loop or so for doing this?

Answer 1

Something like this:

private IList<string> SplitIntoChunks(string text, int chunkSize)
{
    List<string> chunks = new List<string>();
    int offset = 0;
    while (offset < text.Length)
    {
        int size = Math.Min(chunkSize, text.Length - offset);
        chunks.Add(text.Substring(offset, size));
        offset += size;
    }
    return chunks;
}

Or just to iterate over:

private IEnumerable<string> SplitIntoChunks(string text, int chunkSize)
{
    int offset = 0;
    while (offset < text.Length)
    {
        int size = Math.Min(chunkSize, text.Length - offset);
        yield return text.Substring(offset, size);
        offset += size;
    }
}

Note that this splits into chunks of UTF-16 code units, which isn't quite the same as splitting into chunks of Unicode code points, which in turn may not be the same as splitting into chunks of glyphs.

Answer 2

Though this question meanwhile has an accepted answer, here's a short version with the help of regular expressions. Purists may not like it (understandably) but when you need a quick solution and you are handy with regexes, this can be it. Performance is rather good, surprisingly:

string [] split = Regex.Split(yourString, @"(?<=\G.{512})");

What it does? Negative look-backward and remembering the last position with \G. It will also catch the last bit, even if it isn't dividable by 512.

Answer 3

using Jon's implementation and the yield keyword.

IEnumerable<string> Chunks(string text, int chunkSize)
{
    for (int offset = 0; offset < text.Length; offset += chunkSize)
    {
        int size = Math.Min(chunkSize, text.Length - offset);
        yield return text.Substring(offset, size);
    }
}