<?php

$re = "/\A[(]?[0-9]{3}[)]?[ ,-]?[0-9]{3}[ ,-]?[0-9]{4}\z/"; 
$strs = array("909-999-9999", "909 999 9999", "(909) 999-9999", "(909) 999 9999", "999 999 9999","9999999999"); 
$vals = preg_grep($re, $strs);
print_r($vals);