Question

How do I get “Lrumipsm1” from “Lörum ipsäm 1!”?

So what I need is to only get a-z and 0-9 from a string, using php.

Answer 1

E.g. by using a regular expression (pcre) and replacing all characters that are not within the class of “acceptable” characters by ”.

$in = "Lörum ipsäm 1!";
$result = preg_replace('/[^a-z0-9]+/i', '', $in);
echo $result;

see also: http://docs.php.net/preg_replace

edit:
[a-z0-9] is the class of all characters a….z and 0…9
[^...] negates a class, i.e. [^a-z0-9] contains all characters that are not within a…z0…9
+ is a quantifier with the meaning “1 or more times”, [^a-z0-9]+ matches one or more (consecutive) characters that are not within a…z0..9.
The option i makes the pattern case-insensitive, i.e. [a-z] also matches A…Z