Javascript: Getting error while validating number using regular expression

Question

I am trying to validate telephone number in this format : (xxx) xxx-xxxx. For that I have used regular expression but it doesn't validate when I enter incorrect format and click on submit it doesn't show any error. Can anyone help me to identify an issue?

code:

<!DOCTYPE html>
<html>
<head>
 <title>NumerValidation</title>
</head>
<body>
  <form name="myform" id="myform" action="" onsubmit="return validateForm()" method="post">
   <table cellspacing="2" cellpadding="2" border="0">
   <tr>
    <td align="right">Telephone number</td>
    <td><input type="text" name="phone" size="28" placeholder="(555) 555-5555"/></td>
   </tr>
   <tr>
    <td align="right"></td>
    <td><input type="submit" value="Submit" /> </td>
   </tr>
  </table>
  </form>

  <script>

   function validateForm() {

   var phone = document.myform.phone; 
   var regPhone = /^\(?[(]?[0-9]{3}[)]?[-\s]?[0-9]{3}[-]?[0-9]{4}$/im;

    //var phone = /^\(?([0-9]{3})\)?[-]?([0-9]{3})[-]?([0-9]{4})$/;  
    if(phone.value.match(regPhone)) 
    {  
     return true;  
    }  
    else  
    {  
     window.alert("Please enter Telephone number in (xxx) xxx-xxxx format.");  
     return false;  
    } 
   } 
  </script>

</body>
</html>

That's because your regex does not require any braces or whitespace or similar, as they are always followed by `?`. In other words, `/^\(?[(]?[0-9]{3}[)]?[-\s]?[0-9]{3}[-]?[0-9]{4}$/im.test("123456890") === true`. — ASDFGerte, Oct 21 '17 at 23:54
Possible duplicate of [Validate phone number with JavaScript](https://stackoverflow.com/questions/4338267/validate-phone-number-with-javascript) — Alan Larimer, Oct 21 '17 at 23:55
You have for example added `\(?` which means "possibly a brace" but if there is none that's no problem. — ASDFGerte, Oct 21 '17 at 23:59
Also, it appears you are missing a semicolon on line 25 (declaration of regPhone). — JG7, Oct 22 '17 at 00:01
@ASDFGerte I have modified regular expression **var regPhone = /^\([(][0-9]{3}[)][\s][0-9]{3}[-][0-9]{4}$/im;** . but it still doesn't work — Riya, Oct 22 '17 at 01:03

score 0 · Answer 1 · answered Oct 21 '17 at 23:51

0

use this regular expression

^$\d{3}$\s{0,}\d{3}\s{0,}-\s{0,}\d{4}$

it matches

(111)111 - 1111
(111) 111 - 1111
(111) 111- 1111
(111) 111- 1111
(111) 111-1111
(111) 111 - 1111

incase the user adds spaces at the beginning or end of the phone number, you have to trim it with

value = value.trimLeft();
value = value.trimRight();

if you don't trim white spaces at the beginning and end of the input, the regexp will fail even if the user inputs valid number

answered Oct 21 '17 at 23:51

0.sh

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what kind if input do you use to test it, because it seems to work over here – 0.sh Oct 22 '17 at 00:07
I used 1234567890 to test it – Riya Oct 22 '17 at 00:09
how do you input it in the input box ? which format was supposed to fail but passed ? – 0.sh Oct 22 '17 at 00:16

Javascript: Getting error while validating number using regular expression

1 Answers1