What are the alternatives to Split a string in c# that don't use String.Split()

Question

I saw this question that asks given a string \"smith;rodgers;McCalne\" how can you produce a collection. The answer to this was to use String.Split.

If we don\'t ha

Answer 1

Regex?

Or just Substring. This is what Split does internally

Answer 2

It's reasonably simple to write your own Split equivalent.

Here's a quick example, although in reality you'd probably want to create some overloads for more flexibility. (Well, in reality you'd just use the framework's built-in Split methods!)

string foo = "smith;rodgers;McCalne";
foreach (string bar in foo.Split2(";"))
{
    Console.WriteLine(bar);
}

// ...

public static class StringExtensions
{
    public static IEnumerable<string> Split2(this string source, string delim)
    {
        // argument null checking etc omitted for brevity

        int oldIndex = 0, newIndex;
        while ((newIndex = source.IndexOf(delim, oldIndex)) != -1)
        {
            yield return source.Substring(oldIndex, newIndex - oldIndex);
            oldIndex = newIndex + delim.Length;
        }
        yield return source.Substring(oldIndex);
    }
}

Answer 3

You make your own loop to do the split. Here is one that uses the Aggregate extension method. Not very efficient, as it uses the += operator on the strings, so it should not really be used as anything but an example, but it works:

string names = "smith;rodgers;McCalne";

List<string> split = names.Aggregate(new string[] { string.Empty }.ToList(), (s, c) => {
  if (c == ';') s.Add(string.Empty); else s[s.Count - 1] += c;
  return s;
});