How to match the first occurrence of a character and split it

Question

I have a text file from which I want to store Keys and Values in a String array.

In this case, Key is something like &

Answer 1

On this way you can read each line of the text file. You fill the json with Key = until the ":" Value= From the ":"

Dictionary<string, string> yourDictionary = new Dictionary<string, string>();
string pathF = "C:\\fich.txt";
StreamReader file = new StreamReader(pathF, Encoding.Default);
string step = "";
List<string> stream = new List<string>();
while ((step = file.ReadLine()) != null)
{
    if (!string.IsNullOrEmpty(step))
    {
        yourDictionary.Add(step.Substring(0, step.IndexOf(':')), step.Substring(step.IndexOf(':') + 1));
    }
}

Answer 2

Here's one way to do it with regex (comments in code):

  string[] lines = {@"Input File : 'D:\myfile.wav'", @"Duration: 00:00:18.57"};
  Regex regex = new Regex("^[^:]+");
  Dictionary<string, string> dict = new Dictionary<string, string>();

  for (int i = 0; i < lines.Length; i++)
  {
    // match in the string will be everything before first :,
    // then we replace match with empty string and remove first
    // character which will be :, and that will be the value
    string key = regex.Match(lines[i]).Value.Trim();
    string value = regex.Replace(lines[i], "").Remove(0, 1).Trim();
    dict.Add(key, value);
  }

It uses pattern ^[^:]+, which is negated class technique to match everything unless specified character.

Answer 3

Basically, you do not want to split your entire string, but to skip all the content before encountering first ':' char plus one symbol (':' itself).

var data = line.Substring(line.IndexOf(':') + 1);

Or if you really want solution with Split:

var data = string.Join(":", line.Split(':').Skip(1));

Here, we first split the string into array, then skip one element (the one we are trying to get rid of), and finally construct a new string with ':' between elements in the array.

Answer 4

you need to read put information to String Line after that, do this.

String Key = Line.Split( ':' )[0];
String Value = Text.Substring( Key.Length + 1, Text.Length - Property.Length - 1 );

Answer 5

Using regular expression captures

private static Regex _regex = new Regex(@"^([\p{L}_ ]+):?(.+)$");

....

Match match = _regex.Match(line);
if (match.Success)
{
    string key = match.Groups[1].Captures[0].Value;
    string value = match.Groups[2].Captures[0].Value;
}

The regexp is a static member to avoid compiling it for every usage. The ? in the expression is to force lazy behavior (greedy is the default) and match the first :.

Link to Fiddle.

Edit

I've updated the code and fiddle after your comment. I think this is what you mean:

Key: Any letter, underscore and whitespace combination (no digits) Value: anything Separator between key and value: :