Question

I have been trying to use regex but I cant seem to get it to work. I’m trying to use regex with the asp.net RegularExpressionValidator. What I want it to do is to basically disallow leading and trailing spaces only.

So,

"hello "                 // would not work.
"hello my name is"       // would work.

But in all my attempts it says bad input no matter what I put in.

Here is what I used:

^\s[a-z]+\s$

Can someone please provide one that works?

And also, what does it mean when someone says the regex returned a match?

Edit:

I have tried all the solutions in the thread and none of them work for me. Maybe it is something else wrong and not the regex? Heres is the relevant code:

                            <InsertItemTemplate>
                            <asp:TextBox CssClass="tbUpdateSummary" TextMode="MultiLine" Text='<%# Bind("updateSummary") %>'
                                ID="tbUpdateSummaryInsert" runat="server"></asp:TextBox>
                            <asp:RequiredFieldValidator ID="valUpdateSummaryInsert1" runat="server" Display="None"
                                ControlToValidate="tbUpdateSummaryInsert" ErrorMessage="Update summary must not be empty.">
                            </asp:RequiredFieldValidator>
                            <asp:RegularExpressionValidator ValidationExpression="^\s+|\s$" ID="valUpdateSummaryEdit2"
                                runat="server" Display="None" ControlToValidate="tbUpdateSummaryInsert"  ErrorMessage="Update summary must not contain leading or trailing spaces."> </asp:RegularExpressionValidator>
                            <%--Put c# code to validate length (max 200)--%>
                            <asp:CustomValidator></asp:CustomValidator>
                        </InsertItemTemplate>

^[^\s].+[^\s]$ <======= This one actually works!!

Answer 1

Try this regex it should match everything that don’t have a white space at the start and end

^[^\s].+[^\s]$