here is how Superglobals are defined in PHP

Superglobals — Built-in variables that are always available in all scopes

And here is how $GLOBALS are defined here

$GLOBALS — References all variables available in global scope

I'm aware of the existence of 'various' scopes like local, static, closure, namespace and maybe more in PHP and I'm not looking for a reason to nitpick wording inaccuracies in the definitions. However I wonder why $GLOBALS was defined differently from Superglobals in terms of availability, not this way:

$GLOBALS — References all variables available in all scopes

here is how Superglobals are defined in PHP

Superglobals — Built-in variables that are always available in all scopes

And here is how $GLOBALS are defined here

$GLOBALS — References all variables available in global scope

I'm aware of the existence of 'various' scopes like local, static, closure, namespace and maybe more in PHP and I'm not looking for a reason to nitpick wording inaccuracies in the definitions. However I wonder why $GLOBALS was defined differently from Superglobals in terms of availability, not this way:

$GLOBALS — References all variables available in all scopes

• php
• global
• scopes
• superglobals
• global-scope

Share Improve this question Follow asked Mar 6 at 12:31 RedgardRedgard 3766 bronze badges 11

• ...because it only is intended to include global variables, not all variables. Are you asking why the wording is like that, or why that design decision was made? I would say...why would you want a variable that referenced all variables from all scopes? And actually how would that work in practice? If I define a variable in my function, I don't want it also available in another function. – ADyson Commented Mar 6 at 12:37
• 1 Maybe an easy way to understand this is: $GLOBALS is a superglobal. – KIKO Software Commented Mar 6 at 12:55
• @ADyson I'm asking what's the reason for saying $GLOBALS are available in global scope, and not saying $GLOBALS are available in all scopes, while a variable that belongs to the $GLOBALS array is available in all scopes, isn't it? – Redgard Commented Mar 6 at 13:12
• @YourCommonSense You're welcome to change the title. It's not that important. – Redgard Commented Mar 6 at 13:15
• 1 implicitly promting a reader to think that there is such a thinkg like a "global scope" and such a thin like "all scopes"...yes, those things exist. So it should definitely prompt the reader about them. I'm not clear what you mean by this remark. – ADyson Commented Mar 6 at 13:28

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There is no difference in their visibility. $GLOBALS is a superglobal as well. This means that you can access that $GLOBALS from variable anywhere in your code, in any scope.

Regarding your confusion, I think you've misunderstood what the documentation is telling you.

The bit from the documentation of $GLOBALS that you quoted:

$GLOBALS — References all variables available in global scope

isn't talking about the availability of $GLOBALS itself (that's already described in the superglobals documentation).

Instead it's telling you what the contents of $GLOBALS is. What $GLOBALS contains is all variables which have global scope.

And the fact that they're referenced by $GLOBALS then gives you a nice way to read them from any scope, not just the global scope (this removes the need for you to write things like global $variable; for every global you want to reference inside a function, for example). Note that as of PHP 8.1, $GLOBALS, global variables cannot be modified via it - so it provides a read-only view of those values.