Regular expression validator for 10 digit and numbers only c# asp.net

Question

i want a regular expression validator that will have numbers only till 10 digits

i have tried this but it is for only numbers and not for numbers of digit

<asp:RegularExpressionValidator ID="rvDigits" runat="server" ControlToValidate="txtMobId"
                                ErrorMessage="Enter numbers only till 10 digit" ValidationGroup="valGroup" ForeColor="Red"
                                ValidationExpression="\d+" />

Solution 1

You need to use a limiting quantifier {min,max}.

If you allow empty input, use {0,10} to match 0 to 10 digits:

ValidationExpression="^[0-9]{0,10}$"

Else, use {1,10} to allow 1 to 10 digits:

ValidationExpression="^[0-9]{1,10}$"

Or to match exactly 10-digit strings omit the min, part:

ValidationExpression="^[0-9]{10}$"

Also, note that server-side validation uses .NET regex syntax, and \d matches more than digits from 0 to 9 in this regex flavor, thus prefer [0-9]. See \d is less efficient than [0-9].

Besides, it seems you can omit ^ and $ altogether (see MSDN Regular Expressions in ASP.NET article):

You do not need to specify beginning of string and end of string matching characters (^ and $)—they are assumed. If you add them, it won't hurt (or change) anything—it's simply unnecessary.

Most people prefer to keep them explicit inside the pattern for clarity.

Solution 2

Test this answer:

<asp:RegularExpressionValidator ID="rvDigits" runat="server" ControlToValidate="txtMobId" ErrorMessage="Enter numbers only till 10 digit" ValidationGroup="valGroup" ForeColor="Red" ValidationExpression="[0-9]{10}" />

Comments

[mnieto]

if you need a range up to 10 digits \d{1,10}

[Rahul Hendawe]

Possibe Duplicate Regular expression for 10 digit number without any special characters

[Chris]

My reading is the OP wants exactly 10 digits. You might want to include that in your answer too...

[Wiktor Stribiżew]

@Chris: I see only till 10 digits. I guess from ... till... ? Well, I added that case to the answer.

[Chris]

Yeah, its not exactly clear. My reading is "input numbers until you have 10 digits". The title also suggests 10 digits (and not less). Anyway, you've added it now. Thank you. :)