create superglobal variables in php?

Question

is there a way to create my own custom superglobal variables like $_POST and $_GET?

score 52 · Accepted Answer · answered May 07 '09 at 13:58

52

Static class variables can be referenced globally, e.g.:

class myGlobals {

   static $myVariable;

}

function a() {

  print myGlobals::$myVariable;

}

answered May 07 '09 at 13:58

Scott Reynen

3,530
18
17

2

You sir, made my day. But does it only work inside classes? Is there a way to do this outside a class? – Mauker Jun 18 '15 at 14:36

score 37 · Answer 2 · edited May 24 '21 at 09:29

37

Yes, it is possible, but not with the so-called "core" PHP functionalities. You have to install an extension called runkit7: Installation

After that, you can set your custom superglobals in php.ini as documented here: ini.runkit.superglobal

edited May 24 '21 at 09:29

Umair Khan

1,684
18
34

answered May 13 '14 at 17:35

Piero Mori

449
4
4

7

This is the only answer on this question that actually answers it. The other ones are basically 'no, but you can do this instead'. +1, I wish it were higher. – Chiri Vulpes Mar 15 '15 at 11:13
For Swoole's HTTP Server, if we need to set Super Globals, runkit is also best use case there. – Fakhar Anwar Jul 24 '20 at 09:04

score 19 · Answer 3 · edited Jul 22 '20 at 06:24

19

I think you already have it - every variable you create in global space can be accessed using the $GLOBALS superglobal like this:

// in global space
$myVar = "hello";

// inside a function
function foo() {
    echo $GLOBALS['myVar'];
}

edited Jul 22 '20 at 06:24

BushBush Saur

44
6

answered May 07 '09 at 14:20

OneNerd

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2

What's the performance of using $GLOBALS array compared to simply using the variable itself? – Pacerier Jun 10 '13 at 15:46
1

^ Same as any other nested array, it's essentially negligible. Having your own superglobal is appealing more for ease of use (less typing) and aesthetics. – simontemplar Nov 07 '13 at 01:40
1

$GLOBALS are not SUPERglobals! Every global variable must be imported into a function scope using the `global` statement. Superglobals have no such limitation. – Cláudio Silva Oct 31 '18 at 16:50
@Cláudio Silva $GLOBALS are super globals according to [php.net](https://www.php.net/manual/en/language.variables.superglobals.php) Accessing $GLOBALS inside a function does work. – Marcus Nov 27 '20 at 22:43
What I meant was the variables accessible trough $GLOBALS are those that need to be imported explicitly via `global $varName` so they are not superglobals. Also, superglobal variables are not present on $GLOBALS. But the $GLOBALS array is, indeed, superglobal. – Cláudio Silva Sep 17 '21 at 18:06

score 7 · Answer 4 · answered May 08 '11 at 13:58

7

   Class Registry {
 private $vars = array();
 public function __set($index, $value){$this->vars[$index] = $value;}
 public function __get($index){return $this->vars[$index];}
}
$registry = new Registry;

function _REGISTRY(){
    global $registry;
    return $registry;
}

_REGISTRY()->sampleArray=array(1,2,'red','white');

//_REGISTRY()->someOtherClassName = new className;
//_REGISTRY()->someOtherClassName->dosomething();

class sampleClass {
    public function sampleMethod(){
        print_r(_REGISTRY()->sampleArray); echo '<br/>';
        _REGISTRY()->sampleVar='value';
        echo _REGISTRY()->sampleVar.'<br/>';

    }
}

$whatever = new sampleClass;

$whatever->sampleMethod();

answered May 08 '11 at 13:58

Guntarss

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5

Adding a description to this answer would help people to understand what you have done. – starbeamrainbowlabs Sep 06 '16 at 10:37
This approach demonstrates the registry pattern and requires you to type `_REGISTRY()->` every time you want to access the variable for reading or writing. The sampleClass is a demonstration of reading and writing to the registry from within the scope of a function. Personally I'm not a fan of the registry pattern, despite resorting to it often, but I do enjoy having a dedicated class, not intended to be constructed, where I can store a bunch of static variables, as shown in the accepted answer. – Ultimater Nov 27 '18 at 05:33

score 7 · Answer 5 · answered Sep 23 '11 at 18:23

One other way to get around this issue is to use a static class method or variable.

For example:

class myGlobals {

   public static $myVariable;

}

Then, in your functions you can simply refer to your global variable like this:

function Test()
{
 echo myGlobals::$myVariable;
}

Not as clean as some other languages, but at least you don't have to keep declaring it global all the time.

score 6 · Answer 6 · answered Sep 25 '13 at 18:12

6

No

There are only built-in superglobals listed in this manual

answered Sep 25 '13 at 18:12

Geo

12,666
4
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score 5 · Answer 7 · answered May 07 '09 at 12:59

5

Not really. though you can just abuse the ones that are there if you don't mind the ugliness of it.

answered May 07 '09 at 12:59

Rik Heywood

13,816
9
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score 2 · Answer 8 · answered May 07 '09 at 15:59

2

You can also use the Environment variables of the server, and access these in PHP This is a good way to maybe store global database access if you own and exclusively use the server.

answered May 07 '09 at 15:59

Ian Warner

1,058
13
32

1

Note that this will only work for strings, and not complex data types like objects. – starbeamrainbowlabs Sep 06 '16 at 10:38

T.Todua · Answer 9 · 2019-05-01T07:19:19.770

1

possible workaround with $GLOBALS:

file.php:

$GLOBALS['xyz'] = "hello";

any_included_file.php:

echo $GLOBALS['xyz'];

edited May 01 '19 at 07:19

answered Dec 23 '17 at 10:14

T.Todua

53,146
19
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237

I don't think this answers the question. The point of a superglobal is that you can reference it without either `global` or `$GLOBALS`, so this is just two ways to access a normal global. – Matthijs Kooijman Apr 30 '19 at 14:38

score 1 · Answer 10 · answered Mar 15 '21 at 23:18

One solution is to create your superglobal variable in a separate php file and then auto load that file with every php call using the auto_prepend_file directive.

something like this should work after restarting your php server (your ini file location might be different):

/usr/local/etc/php/conf.d/load-my-custom-superglobals.ini

auto_prepend_file=/var/www/html/superglobals.php

/var/www/html/superglobals.php

<?php
  $_GLOBALS['_MY_SUPER_GLOBAL'] = 'example';

/var/www/html/index.php

<?php
  echo $_MY_SUPER_GLOBAL;

MiMFa · Answer 11 · 2023-01-02T13:14:11.793

Actually, there is no direct way to define your own superglobal variables; But it's a trick that I always do to access simpler to my useful variables!

class _ {
    public static $VAR1;
    public static $VAR2;
    public static $VAR3;
}

Then I want to use:

function Test() {
    echo \_::$VAR2;
}

Notice: Don't forget to use \ before, If you want to use it everywhere you have a namespace too...

Enjoy...

create superglobal variables in php?

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