php validate phone number

[Hailwood]

Hi there

 

 

ive been looking into preg_replace,

 

 

how do i validate a phone number in the format of

 

 

^+[0-9]$

is the closest i can get

 

 

it needs to begin with a + can have as many numbers as needed but thats it.

[Pikachu2000]

If they all, without fail, begin with a +, and contain a string of digits of no certain length, it would probably be easiest to just validate the form field as numeric, and concatenate the + to the string in the code.

 

I.E., have the user enter the number (1234567890), then

 

if(is_numeric($_POST['tel_no'])) {
     $tel_no = "+";
     $tel_no .= $_POST['tel_no'];
}

[Daniel0]

If they all, without fail, begin with a +, and contain a string of digits of no certain length, it would probably be easiest to just validate the form field as numeric, and concatenate the + to the string in the code.

 

I.E., have the user enter the number (1234567890), then

 

if(is_numeric($_POST['tel_no'])) {
     $tel_no = "+";
     $tel_no .= $_POST['tel_no'];
}

 

So 1.234e56 is a valid phone number in your eyes?

[Andy-H]

if (substr($_POST['tel_no'], 0, 1) == '+')
{
   $num = substr($_POST['tel_no'], 1);
}
else
{
   $num = $_POST['tel_no'];
}

if (!ctype_digit($num))
{
   echo $num . ' is not a valid telephone number.';
}
else
{
   $num = '+' . $num;
//...
}

 

//edit missed a ; lol

[Daniel0]

For the sake of readability, I'd just use a regex in this case:

 

if (!preg_match('#^\+\d+$#', $number)) {
    // it's invalid
}

 

Alternately:

 

if ($number[0] != '+' || !ctype_digit(substr($number, 1))) {
    // it's invalid
}