$re = '/(?:^\d{1,3}(?:\.?\d{3})*(?:,\d{2})?$)|(?:^\d{1,3}(?:,?\d{3})*(?:\.\d{2})?$)/m';
$str = '1
1234
123456
1.234
123.456
1.234.567
1,23
12345,67
1234567,89
1.234,56
123.456,78
1.234.567,89
';
preg_match_all($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