$re = '/^(.*[^-])\s(\d.*)$/m';
$str = 'Friedr 5 ichstr 4
Friedrichstr. 44
Friedrichstr. 4a
Friedrichstr. 4A
Friedrichstr. 44a
Friedrichstr. 423B
Friedrichstr. 4a-5
Friedrichstr. 4-5A
Friedrichstr. 4 - 5
Friedrichstr. 4A - 34B
';
preg_match_all($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