$re = '/^(\+)?234[0-9]*?.*/m';
$str = '0000 000 0000
01 000 0000
+234 1 000 0000
0000-000-0000
00000000000
234 000 000 0000
234(000)000-0000
234(000)000 0000
+234(000)000 0000
+234(000) 000 0000
+234(000)000-0000
2340000000000
+2340000000000
55523456565';
preg_match_all($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