What is the most efficient way to detect if a string contains a number of consecutive duplicate characters in C#?

Question

For example, a user entered \"I love this post!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\"

the consecutive duplicate exclamation mark \"!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\" should b

Answer 1

The following regular expression would detect repeating chars. You could up the number or limit this to specific characters to make it more robust.

        int threshold = 3;
        string stringToMatch = "thisstringrepeatsss";
        string pattern = "(\\d)\\" + threshold + " + ";
        Regex r = new Regex(pattern);
        Match m = r.Match(stringToMatch);
        while(m.Success)
        {
                Console.WriteLine("character passes threshold " + m.ToString());
                m = m.NextMatch();
         }