Online PHP editor | output for ZIgO7

<?php $test = ['07511 111111', '+447511 111111', '+44 (0) 7511 111111', '07211 111111' '3749853857', '0712121211233']; foreach ($test as $input) { //step 1 - reduce it to digits: preg_match_all('([\+]{0,1}[^ ][0-9]+)', $input, $digits); $digits = implode($digits[0]); //now for step 2.. start by removing +44 and replacing it with 0 if (substr($digits, 0, 3) == '+44') { $digits = str_replace('+44', '0', $digits); } //by this point we should have just a UK-style number, but we must validate it: if ((substr($digits, 2, 1) > 3) && strlen($digits) == 11) { //valid UK mobile number! echo "valid UK mobile number $digits"; } }