$re = '/[0-9]/m';
$str = 'Create a regex that will recognize valid non-temporary Canadian social insurance numbers (SIN). An SIN has nine digits in three groups of three separated by a hyphen. Temporary SINs start with a 9.
956-943-987
123-456-987
123456789
908764392
956 - 543 - 432
956 - 543 - 432';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php