$re = '/^\+(?:7(?: (?:\((?:\d{1,3}(?:\)(?: (?:\d{1,3}(?:-(?:\d{1,2}(?:-\d{0,2})?)?)?)?)?)?)?)?)?)?$/m';
$str = '+
+7
+7
+7 (
+7 (1
+7 (12
+7 (123
+7 (123)
+7 (123)
+7 (123) 4
+7 (123) 45
+7 (123) 456
+7 (123) 456-
+7 (123) 456-7
+7 (123) 456-78
+7 (123) 456-78-
+7 (123) 456-78-9
+7 (123) 456-78-90
+7 (123) 456-78-902
+7 (123) 45678-90
+7 123 456-78-90';
preg_match_all($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