Custom validator - start with issue

Question

<asp:RegularExpressionValidator ID="rev" runat="server"
                    ControlToValidate="txt" Display="Dynamic"                    
                    Text="invalid"
                    ValidationExpression="[AB]\w*" />

The above custom validator should force user to enter values that start with AB and CD but don't know how to add that second CD parameter?

Answer 1

Try this for the regex

(AB|CD)\w*

The | represents an OR

Alternation with The Vertical Bar or Pipe Symbol

Also, have a look at the MSDN guide on Regex's.

I do not think that you want to use the [] judging from your question. Try () instead.

Here is the MSDN documentation I mentioned above

Regular Expressions