This function quickly grabs the 10 digit phone number from a string, formatted as (xxx) xxx-xxxx.

10digitphone.php

<?php
// This function quickly grabs the 10 digit phone number from a string. 
// Works with most user input. 
// Standard US phone number format only.
// Note: For storage, always store what the user gives you (ex: 555-123-1234 until 5pm, after that call 555-123-1234)

function extract10digitphone( $str, $format = '(%s) %s-%s' ) {
	$regex = '/([0-9]{3}).*([0-9]{3}).*([0-9]{4})/mU';
	
	if ( preg_match( $regex, $str, $match ) ) {
		return sprintf( $format, $match[1], $match[2], $match[3] );
	}
	
	return false;
}



// Example usage. Some of these are *expected* to fail
$test_cases = explode("\n", "(+351) 282 43 50 50
90191919908
555-8909
001 6867684
001 6867684x1
1 (234) 567-8901
1-234-567-8901 x1234
1-234-567-8901 ext1234
1-234 567.89/01 ext.1234
1(234)5678901x1234
(123)8575973
(0055)(123)8575973
1-234-567-8901
1-234-567-8901 x1234
1-234-567-8901 ext1234
1 (234) 567-8901
1.234.567.8901
1/234/567/8901
12345678901");

echo '<pre>';
foreach( $test_cases as $phone ) {
  $formatted = extract10digitphone( $phone );
  echo $phone . "\n" . ($formatted ?: '[false]') . "\n\n";
}
echo '</pre>';



/*
Output:


(+351) 282 43 50 50
[false]

90191919908
(901) 919 - 1990

555-8909
[false]

001 6867684
(001) 686 - 7684

001 6867684x1
(001) 686 - 7684

1 (234) 567-8901
(234) 567 - 8901

1-234-567-8901 x1234
(234) 567 - 8901

1-234-567-8901 ext1234
(234) 567 - 8901

1-234 567.89/01 ext.1234
(234) 567 - 1234

1(234)5678901x1234
(234) 567 - 8901

(123)8575973
(123) 857 - 5973

(0055)(123)8575973
(005) 123 - 8575

1-234-567-8901
(234) 567 - 8901

1-234-567-8901 x1234
(234) 567 - 8901

1-234-567-8901 ext1234
(234) 567 - 8901

1 (234) 567-8901
(234) 567 - 8901

1.234.567.8901
(234) 567 - 8901

1/234/567/8901
(234) 567 - 8901

12345678901
(123) 456 - 7890
*/