Split string into set of sub-strings with given length, delimited by separator

Question

Looking for best solution to create a number of sub-strings such that the length of each sub-string does not exceed the length value in parameter. It should converts spaces to specified separator(let's use comma as an example) when enclosed in sub-strings and removes extraneous spaces. Example:

input string = "Smoking is one of the leading causes of statistics"

length of substring = 7

result = "Smoking,is one,of the,leading,causes,of,statist,ics."

input string = "Let this be a reminder to you all that this organization will not tolerate failure."

length of substring = 30

result = "let this be a reminder to you,all that this organization_will not tolerate failure."

Answer 1

The hard part is handling the spaces, I think. This is what I came up with

  private string SplitString(string s, int maxLength)
  {
    string rest = s + " ";
    List<string> parts = new List<string>();
    while (rest != "")
    {
      var part = rest.Substring(0, Math.Min(maxLength, rest.Length));
      var startOfNextString = Math.Min(maxLength, rest.Length);
      var lastSpace = part.LastIndexOf(" ");
      if (lastSpace != -1)
      {
        part = rest.Substring(0, lastSpace);
        startOfNextString = lastSpace;
      }
      parts.Add(part);
      rest = rest.Substring(startOfNextString).TrimStart(new Char[] {' '});
    }

    return String.Join(",", parts);
  }

Then you can call it like this

  Console.WriteLine(SplitString("Smoking is one of the leading causes of statistics", 7));
  Console.WriteLine(SplitString("Let this be a reminder to you all that this organization will not tolerate failure.", 30));

and the output is

Smoking,is one,of the,leading,causes,of,statist,ics
Let this be a reminder to you,all that this organization,will not tolerate failure.