Regular Expression should not allow numbers alone

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I want regular expression that can accept numbers and alphabets or just alphabets but not numbers only.

I am new to this expressions, any one suggest me the expression.

valid:

alphabets + numerics

alphabets only

numerics + alphabets

Invalid:

0-9(numerics only)

Posted 7-Nov-12 19:39pm

PBGuy

Updated 5-Jan-18 0:38am

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MT_ · Answer 1 · 2012-11-07T20:38:00

Solution 1

Hi,
Try following regex

^\d*[a-zA-Z]{1,}\d*

This will be valid if string has atleast 1 alphabet and any number of digit.

I tried above regex using C# code I shared in the comment for following string
abc : Valid,
abc1: Valid,
1abc: Valid,
111: Invalid
a1b1c1: Valid

Thanks
Milind

Posted 7-Nov-12 20:38pm

MT_

Updated 7-Nov-12 21:42pm

v3

Comments

[no name] 8-Nov-12 3:13am

If the string is like:

123abc ,is treated as invalid , but it can be allowed.

MT_ 8-Nov-12 3:19am

I tried this
string testing = "123abc";//also tried 123,abc,1abc etc
Regex regex = new Regex(@"[a-zA-Z]{1,}\d*");
Console.WriteLine(regex.IsMatch(testing));
And it returned "true"

[no name] 8-Nov-12 3:22am

I used this expression in regular expression validator and based on the result a validation call out extender is displayed. It's not working here

MT_ 8-Nov-12 3:23am

can you share code snippet ?

MT_ 8-Nov-12 3:24am

Or else try \d*[a-zA-Z]{1,}\d*

[no name] 8-Nov-12 3:30am

q1r1s1 1q2rs3

MT_ 8-Nov-12 3:32am

What ?

[no name] 8-Nov-12 3:32am

these are treated as invalid

I am looking for an expression that should check one alphabet at least irrespective of position in a string

[no name] 8-Nov-12 3:35am

the string should contain atleast one alphabet irrespective of position

either front or rare or middle ..... atleast one alphabet means, not just numbers alone.

[no name] 8-Nov-12 3:38am

I already told that I dont know regular expressions, sorry for irking u

MT_ 8-Nov-12 3:43am

Try now. Updated the regex in the solution.

[no name] 8-Nov-12 3:49am

solution....?

MT_ 8-Nov-12 3:56am

Check the code I supplied above once again, I have updated regex and some sample.

[no name] 8-Nov-12 4:02am

<asp:RegularExpressionValidator ID="regExValidator" runat="server" ControlToValidate="txtKeyName" Display="None"
ErrorMessage="Numerics Alone are not Allowd" SetFocusOnError="true" ValidationGroup="test" ValidationExpression=".*[a-zA-Z]+.*">

[no name] 8-Nov-12 4:03am

".*[a-zA-Z]+.*" working fine.... thank you for your time...

lokesh jammugani · Answer 2 · 2018-01-05T00:38:00

actually this /^[0-9]*[a-zA-Z_]+[a-zA-Z0-9_]*$/
actually this /^[a-zA-Z0-9_]*[a-zA-Z_]+[a-zA-Z0-9_]*$/
both don't allow numbers alone, both worked perfectly for me and their meaning is
[0-9]* - 0 or more times occurrences of 0-9 numbers any where in the entered string.
[a-zA-Z_]+ at least there must be one character in entered string from a-z, A-Z, _
[a-zA-Z0-9_]* There can be 0 or more repeated characters from a-z, A-Z, 0-9, _ any where in the entered string.
Here the allowed values to your input text-box are a-zA-Z0-9_ and not other than these characters eg:!@#%^&*()+= are not allowed.