Telephone Numbers - A much more interesting example would be matching telephone numbers (US/Canada.) We'll be expecting the number to be in the following form: (###)###-####

Again, whether the phone number is typed like (###) ###-####, or ###-###-#### it will validate successfully. There is also a little more leeway than specifically checking for enough numbers, because the groups of numbers can have or not have parenthesis, and be separated by a dash, period, or space.

$string = "(032)555-5555";
if (preg_match('/^(\(?[0-9]{3,3}\)?|[0-9]{3,3}[-. ]?)[ ][0-9]{3,3}[-. ]?[0-9]{4,4}$/', $string)) {
echo "example 2 successful.";
}