Question

Currently, I have a simple router class that takes URIs and attempts to match them to the incoming request URI. A simple example of a route it might try to match to the request URI would be:

/user/([0-9]+)

So, this would match a request URI of “user/1”.

Now I’m trying to match optional parameters. This works:

/user([/0-9]?)

However, it seems like this would allow any number of slashes in the segment. How can I force the optional segment to be preceded by one slash and then numbers?

Answer 1

Try the following regular expression:

/user(/[0-9]+)?

It will match “/user” followed by “/” plus one or more digits or “/user” alone. If you want to group the digits only you can enclose it in a non-capturing group:

/user(?:/([0-9]+))?

You can enclose it in ^ and $ in the call to preg_match:

preg_match( "/^\/user(?:\/([0-9]+))?$/", "/user/1234", $m);
print_r($m);