Question

Is there a way to trim a string to the first numeric digit from left AND right using standard .NET tools? Or I need to write my own function (not difficult, but I’d rather use standard methods). I need the following outputs for the provided inputs:

Input           Output
-----------------------
abc123def       123
;'-2s;35(r      2s;35
abc12de3f4g     12de3f4

Answer 1

You’ll need to use regular expressions

string TrimToDigits(string text)
{
    var pattern = @"\d.*\d";
    var regex = new Regex(pattern);

    Match m = regex.Match(text);   // m is the first match
    if (m.Success)
    {
        return m.Value;
    }

    return String.Empty;
}

If you want to call this like you normally would the String.Trim() method, you can create it as an extension method.

static class StringExtensions
{
    static string TrimToDigits(this string text)
    {
        // ...
    }
}

And then you can call it like this:

var trimmedString = otherString.TrimToDigits();