Question

I have a regex which I am using to remove everything after a specific character, semi-colon.

        var regex = new Regex(@";(.*)", RegexOptions.Singleline);
        tb.Text = regex.Replace(tb.Text, "");

It seems to work fine, but at times it removes the entire text of the text box. For example all of this code is removed:

;fgkdfgdfgd
;dfgdfkghdfgdf
;sdgfsdfsdfsdf
;dfgdfgdfg

#dont remove this          ;fgdfgdfg

the “#dont remove this” should stay intact because it isn’t after the semi-colon, but it doesn’t? Is something wrong with my regex?

The idea is to remove or trim all comments from a file.

Answer 1

try (UPDATE after comment):

tb.Lines = (
    from l in tb.Lines 
    let x = l.IndexOf (';') 
    select (x >= 0 ? l.SubString (0, x) : l)
).ToArray();

This should run faster than the Regex too…