confirming my understanding of superglobals

jakeone

I've read php.net's explanation of superglobals but could I just confirm my understanding is correct...

1) With PHP v4.2.0, register_globals has been set to "off" which stops PHP predefining variables, e.g. variables submitted via a form for example must be accessed using $_POST('var') instead of just using $var.

2) Will the following function (to loop through an array) work regardless of the register_globals setting?

function add_article()
{
for ($i=0; $i<=5; $i++)
{
echo $GLOBALS['keywords'][$i];
}
}

3) A question like "Can I still use the superglobal array $GLOBALS if register_globals is off?" is missing the point because that's why superglobals exist in the first place - because register_globals is off. Correct?

4) Will I have to go through old code and explicity use $GET, $POST and other superglobals if I don't want the code to break?

5) I've seen $_GLOBALS used instead of $GLOBALS. I assume the former is a typo?

Thanks for clarifying this for me.

drawmack

Originally posted by jakeone 1) With PHP v4.2.0, register_globals has been set to "off" which stops PHP predefining variables, e.g. variables submitted via a form for example must be accessed using $_POST('var') instead of just using $var.

a: Kind of, there are a couple of ways around this. One is to turn register_globals back on in your php.ini file. The other is the extract command (http://www.php.net/extract). Simply put this command in a file that is included at the top of all your other files and you're still rocking with $var

2) Will the following function (to loop through an array) work regardless of the register_globals setting?
function add_article() 
{
    for ($i=0; $i<=5; $i++)
    {
        echo $GLOBALS['keywords'][$i];
    }	
}

Yes

3) A question like "Can I still use the superglobal array $GLOBALS if register_globals is off?" is missing the point because that's why superglobals exist in the first place - because register_globals is off. Correct?

Actually I think you're a little backwards here. I think they turned it off becuase superglobals exist and didn't create superglobals because they turned the switch off. Same idea but one is a little silly when you think about the work flow.

[creating super globals because register globals is off]
Bill: Hey joe why doesn't my $HTTP_POST_VARS work any more?
Joe: They set register_globals to off in php.ini
Bill: Darn now we'll have to make something called superglobals.
Joe: Can't we just change the ini back.
Bill: no we must make superglobals.

4) Will I have to go through old code and explicity use $GET, $POST and other superglobals if I don't want the code to break?

See my answer to number 1

5) I've seen $_GLOBALS used instead of $GLOBALS. I assume the former is a typo?

nope both do the same thing. I prefer $GLOBALS because all the other super globals start with $ except this one and that's confusing.

jakeone

Hi Drawmack

Thanks for the helpful answers!

As for the point about "creating superglobals because register_globals is off", I see what you mean. However, I thought register_globals was switched off to improve security (i.e. reduce potential poisoning scripts with bogus variables) which is why I thought superglobals were "deliberately created", i.e. it wasn't simply a matter of switching register_globals back on because the security holes would have still been there. So I thought the very reason for superglobals to exist were because register_globals was off. I will bear your answer in mind however!

🙂

drawmack

jake,
You could be correct, it just sounded funny the way you said it.