Regex to match alphanumeric and spaces

Question

What am I doing wrong here?

string q = "john s!";
string clean = Regex.Replace(q, @"([^a-zA-Z0-9]|^\s)", string.Empty);
// clean == "johns". I want "john s";

Answer 1

I suspect ^ doesn't work the way you think it does outside of a character class.

What you're telling it to do is replace everything that isn't an alphanumeric with an empty string, OR any leading space. I think what you mean to say is that spaces are ok to not replace - try moving the \s into the [] class.

Answer 2

There appear to be two problems.

1. You're using the ^ outside a [] which matches the start of the line
2. You're not using a * or + which means you will only match a single character.

I think you want the following regex @"([^a-zA-Z0-9\s])+"

Answer 3

The circumflex inside the square brackets means all characters except the subsequent range. You want a circumflex outside of square brackets.

Answer 4

I got it:

string clean = Regex.Replace(q, @"[^a-zA-Z0-9\s]", string.Empty);

Didn't know you could put \s in the brackets