Question

I need to verify if user have entered desired characters in the input field and if he didn’t, I need to format input like this:

Start variable: [phone], +42 (4) 87/654321; [phone]

Desired variable: [phone], [phone], [phone]

So basically I need to clear out all characters from variable that are not numbers and allow only signs like + , ; -.

Because I’m using an AJAX request, I would appreciate code for both PHP and Javascript.

Answer 1

For striping invalid chars from your string use regular expression in PHP and JAVASCRIPT.

PHP

$s = '[phone], +42 (4) 87/654321; [phone]';
$n = preg_replace('~[^\d\+,;-]~', '', $s);
print_r($n); 

JAVASCRIPT

var s = '[phone], +42 (4) 87/654321; [phone]';
var n = s.replace(/[^\d\+,;-]/g, "");
console.log(n);

But better practice is that you show error, if user enters wrong format. You will need some validating to todo…