Phone Number Regex Conditions - php

Question

I need to create a regex function to check phone numbers entered on a phone number field based on these conditions.
• if the number starts with either 6, 8 or 9 and another 7 digits
• or if the number starts with either +656, +658 or +659 and another 7 digits
So basically its singapore phone number with +65 being the country code
6, 8 or 9 are the only starting digit of phone numbers.
I have tried code below but it wont work.
add_filter( 'gform_phone_formats', 'sg_phone_format' );
function sg_phone_format( $phone_formats ) {
$phone_formats['sg'] = array(
'label' => 'Singapore',
'mask' => false,
'regex' => '/^[689]\d{7}$/D|/^(\+656)\d{7}$/D|/^(\+658)\d{7}$/D|/^(\+659)\d{7}$/D',
);
return $phone_formats;
}
Thank you!

Answer 1

I would use this regex pattern for Singapore numbers:
^(?:\+65)?[689][0-9]{7}$
Sample script:
$number = "[phone]";
if (preg_match("/^(?:\+65)?[689][0-9]{7}$/", $number)) {
echo "MATCH";
}

Answer 2

So basically the set condition for a regex match can be found by alternating a grouping of sets that match the occurrences of the desired character or number, like so:
<code>
//$regex = '/\+65+[?:6?8:?:9]+[0-9]{3}+[0-9]{4}/'; //wrong
// Edited the following lines
$regex = '/(?:\+65[6|8|9]+[\d]{7})|(?:\+65[689][\-|\s|\/][0-9]{3}+[\-|\s|\/][0-9]{4})/';
$phone = '[phone],[phone],[phone],[phone],[phone],+658/765/1234,[phone],+6555?:?1231234'; //test string
//Match $var against a regular expression
preg_match_all($regex, $phone, $matches, PREG_SET_ORDER, 0);
//var_dump
var_dump($matches) . " \n";
//print_r
print_r ($matches) . " \n";
//echo single value array();
echo $matches[0][0];
echo "<br />";
echo $matches[1][0];
echo "<br />";
echo $matches[2][0];
echo "<br />";
echo $matches[3][0];
echo "<br />";
echo $matches[4][0];
echo "<br />";
echo $matches[5][0];
echo "<br />";
echo $matches[6][0];
</code>
The result from the above code is as follow:
<pre>
//var_dump
array(6) { [0]=> array(1) { [0]=> string(11) "[phone]" } [1]=> array(1) { [0]=> string(11) "[phone]" } [2]=> array(1) { [0]=> string(13) "[phone]" } [3]=> array(1) { [0]=> string(11) "[phone]" } [4]=> array(1) { [0]=> string(13) "[phone]" } [5]=> array(1) { [0]=> string(13) "+658/765/1234" } }
//print_r
Array ( [0] => Array ( [0] => [phone] ) [1] => Array ( [0] => [phone] ) [2] => Array ( [0] => [phone] ) [3] => Array ( [0] => [phone] ) [4] => Array ( [0] => [phone] ) [5] => Array ( [0] => +658/765/1234 ) )
//echo single value array();
[phone]
[phone]
[phone]
[phone]
[phone]
+658/765/1234
</pre>
You can easily match more personalized regular expressions by setting specific conditions to match the string by escaping additional characters with
\ or any whitespace character with
\s
<code>
// add more characters to regex to match [phone]
$regex = '/\+65[6|8|9]+[\-][0-9]{3}+[\-][0-9]{4}/';
</code>
The result from the modified regular expression will be
<pre>
array(1) { [0]=> array(1) { [0]=> string(13) "[phone]" } }
Array ( [0] => Array ( [0] => [phone] ) )
[phone] //echo one match out of six
</pre>