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

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 dict = new Dictionary();

  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.