$re = '/(?:\d{3}-| # area code without parentheses but with dash
\(\d{3}\)\ ) # -or- area code with parentheses and no dash
\d{3} # first 3 digits
- # second dash
\d{4} # last 4 digits/x';
$str = '(415) 123-2342 and 415-905-1234 are the numbers.';
preg_match_all($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