Globals

Posted: Wed Jan 22, 2003 7:55 pm (21 years, 2 months ago)

Can some one explain to me when I should use global and when I shouldn't? I have been wring a PHP script with functions and having trouble with variables be transfered between the functions and the main script.

Thanks,

Team Member Joined: 06 Jan 2002 Posts: 2564

In a function, no variables are accessible, except those passed along to the function, like this:

function($variable1, $variable2);

So, if you need to access, for example, $PHP_SELF, in your function, you'll need to declare it as global, like so:

Code:

global $PHP_SELF;

You can also do away with this and call $GLOBALS['PHP_SELF'] instead.

Posted: Wed Jan 22, 2003 9:30 pm (21 years, 2 months ago)

Thanks

If I set a variable in a function

Code:

function decreaseturns() {
blah blah blah... lots of code
$turns=value;
blah blah blah... lots of code
}

how would I make it so could access the variable $turns from the rest of the script? (not in the function)

Thanks,

Posted: Wed Jan 22, 2003 9:31 pm (21 years, 2 months ago)

Daniel wrote:

Code:

global $PHP_SELF;

Also... Would I write this in the function or in the main script?

Thanks,

Team Member Joined: 06 Jan 2002 Posts: 2564

I'm not sure. I think you don't need to do anything. But I don't understand why you'd want to do that Question

In the function, like this:

Code:

function blabla($variable1, $variable2) {
global $PHP_SELF;
}

Posted: Thu Jan 23, 2003 9:36 am (21 years, 2 months ago)

Iyonix wrote:

Thanks

If I set a variable in a function

Code:

function decreaseturns() {
blah blah blah... lots of code
$turns=value;
blah blah blah... lots of code
}

how would I make it so could access the variable $turns from the rest of the script? (not in the function)

Thanks,

It would be like this, wouldn't it?

Code:

function decreaseturns() {
blah blah blah... lots of code
$turns=value;
blah blah blah... lots of code
return $turns;
}

$turns = decreaseturns();

Team Member Joined: 06 Jan 2002 Posts: 2564

Well it really depends on what you're looking to do... You might want to return another variable. Anyway, we'll soon find out what Iyonix wants to do Very Happy

.

WebHelper Joined: 30 Jul 2002 Posts: 56 Location: UK

Daniel wrote:

You can also do away with this and call $GLOBALS['PHP_SELF'] instead.

I believe that this is a far more elegant way of doing things, especially with other super-globals such as $SESSION, $_GET and $_POST.

Iyonix wrote:

Thanks

how would I make it so could access the variable $turns from the rest of the script? (not in the function)

This is generally bad practise -- perhaps there is a better way to achieve this?