Question

Given the following string:

string s = "I need drop the 1 from the end of AAAAAAAA1 and BBBBBBBB1"

How can I trim the “1” from any 8 character string that ends in a 1? I got so far as to find a working Regex pattern that finds these strings, and I’m guessing I could use a TrimEnd to remove the “1”, but how I do I modify the string itself?

Regex regex = new Regex("\\w{8}1");

foreach (Match match in regex.Matches(s))
{
    MessageBox.Show(match.Value.TrimEnd('1'));
}

The result I’m looking for would be “I need drop the 1 from the end of AAAAAAAA and BBBBBBBB”

Answer 1

Regex.Replace is the tool for the job:

var regex = new Regex("\\b(\\w{8})1\\b");
regex.replace(s, "$1");

I slightly modified the regular expression to match the description of what you are trying to do more closely.