preg_replace() only replace spaces, symbols with a hyphen

Question

How would I replace anything but letters and numbers with a hyphen? This would be for a slug URL where a person would type in the string they would like for their URL. The problem I’m having is people inputting symbols and many spaces which make the URL invalid.

Also, what would be a good resource to test this so that I don’t have to ask again? Thanks.

Answer 1

The code

$input_url = "This is only an example: do you like it?";
$slug_url = preg_replace("/[^a-zA-Z0-9]/", "-", $input_url);
print($slug_url);

will output

This-is-only-an-example--do-you-like-it-

DEMO