Comma separated string split by length but keeping the comma separation? - arrays

Question

I have a string like this "105321,102305,321506,0321561,3215658" and i need to split this string by the comma (,) and with a specific length, so if the length of each string part is 15, the splited array must be like:
105321,102305
321506,0321561
3215658
I try several ways but i can't find the right approach to do this
The code that i have gives me an error of index out of range:
private static List<string> SplitThis(char charToSplit, string text, int maxSplit)
{
List<string> output = new List<string>();
string[] firstSplit = text.Split(charToSplit);
for(int i = 0; i < firstSplit.Length; i++)
{
string part = firstSplit[i];
if(output.Any() && output[i].Length + part.Length >= maxSplit)
{
output.Add(part);
}
else
{
if(!output.Any())
output.Add(part);
else
output[i] += "," + part;
}
}
return output;
}
Edit: i must say that the comma , must be a part of the amount of the maxSplit variable.

Answer 1

This one would be concise, yet not really performant
private static Pattern P = Pattern.compile("(.{1,15})(,|$)");
private static String[] split(String string) {
Matcher m = P.matcher(string);
List<String> splits = new ArrayList<String>();
while (m.find()) {
splits.add(m.group(1));
}
return splits.toArray(new String[0]);
}
The regular expression in P matches (.{1,15})(,|$):
a sequence of 1 to 15 characters = .{1,15}
followed by , or line ending
the parentheses allow grouping, the content of the first group is what you are interested in

Answer 2

static void Main(string[] args)
{
string originalString = "105321,102305,321506,0321561,3215658";
string[] commaSplit = originalString.Split(',');
string tempString = string.Empty;
List<string> result = new List<string>();
for (int i = 0; i < commaSplit.Length; i++ )
{
if ((tempString.Length + commaSplit[i].Length) > 15)
{
result.Add(tempString);
tempString = string.Empty;
}
if (tempString.Length > 0)
{
tempString += ',' + commaSplit[i];
}
else
{
tempString += commaSplit[i];
}
if (i == commaSplit.Length - 1 && tempString != string.Empty)
{
result.Add(tempString);
}
}
foreach (var s in result)
{
Console.WriteLine(s);
}
Console.ReadKey();
}
This may not be the best solution but it works ;)

Answer 3

what about this?
private static List<string> SplitThis(char charToSplit, string text, int maxSplit)
{
List<string> output = new List<string>();
string[] firstSplit = text.Split(charToSplit);
int i = 0;
while (i < firstSplit.Length)
{
string part = firstSplit[i];
while (part.Length < maxSplit)
{
if (part.Length < maxSplit && i + 1 < firstSplit.Length)
{
if ((part + "," + firstSplit[i + 1]).Length < maxSplit)
{
part += "," + firstSplit[i + 1];
i++;
}
else
{
output.Add(part);
i++;
break;
}
}
else
{
output.Add(part);
i++;
break;
}
}
}
return output;
}