Question

I need to extend this regex to remove space characterless. We use ASP.NET validation using asp:RegularExpressionValidator so I can’t use replace method in between.

Here is my Regex:

\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*

Hre the code

<asp:TextBox ID="tbBIEmailAddress" runat="server" CssClass="inpText" MaxLength="50" />

<asp:RequiredFieldValidator id="reqValBIEmail" runat="server" ControlToValidate="tbBIEmailAddress" Display="Dynamic" ValidationGroup="Checkout">*</asp:RequiredFieldValidator>

<asp:RegularExpressionValidator id="regValBIEmail" runat="server" ControlToValidate="tbBIEmailAddress" ValidationGroup="Checkout" ValidationExpression="\^w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$">*</asp:RegularExpressionValidator>

Answer 1

I know that .Net has the concept of variable number of capture buffers.
So for instance, (asw[^p]+)* should create a capture buffer 1 object that
stores data as an array.

However, its not clear how it would react in this case: (?:([-.]\w+)|\s+)*
Clearly \s is not in the scope of a capture buffer, and should not be included in
the group 1 capture buffer object array. In effect stripping whitespace in the
process of capture. But I didn’t test this.

I could be reading your question wrong though and for all I know, you are using capt groups for just grouping.

added

Your sample might have a typo.
This:
"\^w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$"
should probably be this:
"^\w+([-+.]\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*$"

Its possible that explains your space problem but probably not.