Regex for special characters?

Question

string Val = Regex.Replace(TextBox1.Text, @"[^a-z, A-z, 0-9]", string.Empty);

This expression does not match the character ^ and _ . What should i do to match those values?

One more things is, If TextBox1.Text string value is more than 10, the last string value(11th string value) should match.

Answer 1

Note that the ^ is has special meaning when enclosed in square brackets. It means match everything but those specified in the character class, basically '[]' .

If you want to match "^" and "_" , put the caret (^) in another position than after the opening bracket like so, using the repetition to restrict character length:

[\W_]

That will make sure the characters in the entire string are 10.

Or you escape it using the slash "\\^" .

string Val = Regex.Replace(TextBox1.Text, @"[\W_]", string.Empty);

Answer 2

Your problem is Az .

This matches all ASCII letters A through Z , then the characters that lie between Z and a (which contain, among others, ^ and _ ) , then all ASCII letters between a and z . This means that ^ and _ won't be matched by your regex (as well as the comma and space which you included in your regex as well).

To clarify, your regex could also have been written as

[^a-zA-Z0-9\[\\\]^_` ,]

You probably wanted

string Val = Regex.Replace(TextBox1.Text, @"[^a-zA-Z0-9]", string.Empty);