$re = '/^(([0-9]|10)|([0-9][.,][0]?[1-9][1-9]?))$/m';
$str = '0
5
10
0.5
0.25
5.75
3.03
5.0
3.333
11
20
05
10.5
3.30
';
preg_match_all($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