$re = '/\d{1,3}(?:[.,]\d{3})*(?:[.,]\d{2})/';
$str = '5
5.00
1,000
1,000,000.99
5,99 (european price)
5.999,99 (european price)
0.11
0.00';
preg_match_all($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