Question

Can anybody tell me how to write a regular expression for “no quotes (single or double) allowed and only single hyphens allowed”? For example, "good", 'good', good--looking are not allowed (but good-looking is).

I need put this regex like following:

<asp:RegularExpressionValidator ID="revProductName" runat="server" 
     ErrorMessage="Can not have &quot; or '." Font-Size="Smaller" 
     ControlToValidate="txtProductName" 
     ValidationExpression="^[^'|\"]*$"></asp:RegularExpressionValidator>

The one I have is for double and single quotes. Now I need add multiple hyphens in there. I put like this "^[^'|\"|--]*$", but it is not working.

Answer 1

^(?:-(?!-)|[^'"-]++)*$

should do.

^          # Start of string
(?:        # Either match...
 -(?!-)    # a hyphen, unless followed by another hyphen
|          # or
 [^'"-]++  # one or more characters except quotes/hyphen (possessive match)
)*         # any number of times
$          # End of string