Validating phone number

[PC Nerd]

Hi,

 

Im looking for a way to validate a phone number.  I'm lost as to how to check if its an integer, and to remove any punctuation it is - and the length of the number.  The othe rproblem ive got is that i dont know how many digits ina US mobile phone number. ( Im from Australia.....).

 

If anyone can point me in teh right direction with some functionsetc, id be most greatful.

 

Thanks in advance,

PC Nerd

[hitman6003]

There are 10 digits in a US mobile number.

 

There are two ways...you can force the user to conform to a certain format, e.g. ###-###-####, or you can accept all common formats and check for them, e.g.: (###) ###-####, ##########, ###-###-####, etc.

 

With either one, the easiest way would probably be regex to check for format:

 

$pattern = '/^\d{3}-\d{3}-\d{4}$/';

if (preg_match($pattern, trim($phone_number))) {
  /* Number matches format */
} else {
  /* Number does not match */
}

 

Repeat ad nausem for other patterns.

 

If using the first method, I would recommend using a JS frontend validation so that the user doesn't have to repeatedly resubmit the form if they make errors.  With any method, do (re)validation on the backend.

 

EDIT:  There are 10 digits if you don't include the country code.  If you do, then most US persons will only put "1 ###...", where as most Europeans will put either "+001..." or "001..." for a US country code.

[PC Nerd]

ok

 

assuming that someone only enters the numbers withought the spaces or dashes etc ( which is how ill tell them to enter it) - how would i tell how many digits in the value.

 

eg:

 

$_POST['cell_no'] = "1111111111";

 

how can i tell teh length/dighits in that value?

 

Thanks.

[hitman6003]

Make sure you use "trim" on the user input first to eliminate any leading or trailing spaces.

 

if (is_int($phone_number)) {
  echo "That phone number is " . strlen($phone_number) . " digits long!!";
}

 

or

 

if (preg_match('/^\d{10}$/', $phone_number)) {
  echo "That phone number is " . strlen($phone_number) . " digits long!!";
}

 

PHP's weak typing is helpful here.  You could also use "is_numeric" to test for the numberness of the value.

[PHP_PhREEEk]

Make sure you use "trim" on the user input first to eliminate any leading or trailing spaces.

 

if (is_int($phone_number)) {
  echo "That phone number is " . strlen($phone_number) . " digits long!!";
}

 

$_POST values are always received as strings, so testing with is_int will always return FALSE.

 

PhREEEk

 

 

[hitman6003]

$_POST values are always received as strings, so testing with is_int will always return FALSE.

 

Forgot about that.

 

is_numeric is still a possibility, or you can cast as an int....or just use the regex.

[PHP_PhREEEk]

$_POST values are always received as strings, so testing with is_int will always return FALSE.

 

Forgot about that.

 

is_numeric is still a possibility, or you can cast as an int....or just use the regex.

 

Yeah... well, bottomline is, validating a phone number is a layered problem, and it all begins with what your form accepts.

 

I go the slightly more difficult route, but which ends up more end-user friendly, which is, I use 3 input boxes, one that accepts a 3 digit area code, one that accepts a 3 digit CO code, and a last one that accepts a 4 digit extension. I have never had a problem validating a US phone number in this manner, but I don't have a generic version I can copy and paste real quick... I'm just about off to bed, so good luck to the OP!

 

PhREEEk

[redarrow]

been working on this try it see what you think....

<?php
$a=array("0207-435-7864");
$t=implode(' ',$a);
if(strpos($t,'-')){
$m=str_replace('-',' ',$t);
if(!eregi("^[0-9]{0,100}$",$m)){
echo"Number Format $m";
}else{
echo"Number format incorrect";
}
}
?>

[redarrow]

 

standard way

<?php
if (preg_match('/^[0-9]{3}-[0-9]{3}-[0-9]{4}$/', $phone)) {
echo 'Valid';
}
?>