convert a string and use it as part of URL

[shadow_boi]

Hi,

I am wondering if there a build-in fuction that take a string as input and then replace every non-numbers, non-alphabet characters with "_" (underscore)?

Eg: yes? or no! will be converted to yes__or_no (i will use it as part of the URL)


I guess regular expression can do the trick?
Would anyone please give me the codes?

Thanks.

[jestep]

Try a preg_replace to do it.

Something like:
$new_string = preg_replace("/\W/s","_",$string);

or
$new_string = preg_replace("/[^a-Z0-9]+/","_",$string);

[shadow_boi]

Thanks for the reply.

the first solution works, but the second one doesnt.

Warning: preg_replace() [function.preg-replace]: Compilation failed: range out of order in character class at offset 4

[jestep]

I would just go with the first then. It's more stable anyway.