difference ; and &amp;

difference ; and &

lajkonik86

when using an url to pass variables whats the difference between using ; and & to indicate the next variable?

suntra

Huh ?

Usually it is this way : file.extension?variable1=value1&variable2=value2&variable3=value3

Usually, no " ; "... ?!

bpat1434

Some sites (SMF in particular) will do their own cleaning and validation (which is good). So they'll send one "GET" variable with the others separated by ";". So you could get a URL like:

index.php?action=post;sa=edit;thread=10339154.3

What then happens is that SMF reads the $GET variable and parses it out. It separates by semi-colon, then by equals to get everything it needs. It also does some input validation and puts the result into the $REQUEST array.

That is just an example.

You can change the argument separator in php.ini to ";". Will it make a difference? not really. The only difference I can immediately see is that instead of having to encode the "&" to be "&" you can use the direct character ";". But there is no difference.

lajkonik86

Any idea why SMF uses this approach, any benefits?

bpat1434

No, no idea why they use this approach.

I do know that sometimes it's easier to do it this way. This way you can set up your own filtering mechanism, and if there's more than one $_GET value, you know something is up.

Performance wise, no real benefit. It's just an aesthetic choice. No real reason to use it, unless you want to.

Weedpacket

There's no rule that the record separator HAS to be '&' (or, rather "&" if you're writing it in HTML). This is why PHP offers the arg_separator.output initialisation and arg_separator.input settings.

You could use pretty much anything - except #. None of RFC2616, RFC3986, nor HTML401 specify any more than that. The closest any of them come is HTML401's recommendation that ".... implementors support the use of ';' in place of '&' to save authors the trouble of escaping '&' characters...".

Needless to say, whatever it is you use for the separator (if indeed your query component has a separator), then (a) the server has to recognise it as such, and (b) it has to be urlencoded if you mean it literally.