Limiting a global variable access to my php file only

Question

How to create a variable outside function but which should not be visible outside my php file?

I mean a global variable with single file scope. I don't want to add the function name in global namespace which may clash tomorrow.

Allow me a stupid question: why not just passing it as an argument to your function? you'll solve two problems in this way.. — Damien Pirsy, Dec 25 '11 at 18:13
I want a constant variable to be used by many functions. But it's use is only for my module and should not bother other's code. Actually I'm working on Drupal. — user774250, Dec 25 '11 at 18:16

score 5 · Answer 1 · answered Dec 25 '11 at 18:13

5

You could use an anonymous function:

<?php 

$x = function() {
    $local_global = "nyah can't access me from outside";
    ... do your stuff ...
}

$x();

answered Dec 25 '11 at 18:13

Marc B

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this is not outside a function as per the OP's question but rather inside. – Gordon Dec 25 '11 at 18:25
1

There's only 2 ways to hide a variable in PHP. namespaces, and anonymous functions. – Marc B Dec 25 '11 at 18:27
But I want to use $local_global in multiple functions in my file. Will it work? – user774250 Dec 25 '11 at 18:29
2

$x will be in the global scope. – Gordon Dec 25 '11 at 18:31
1

@user774250: no. go with namespaces instead, then. But then you're stuck with requiring php 5.3 – Marc B Dec 25 '11 at 18:31

score 1 · Answer 2 · answered Dec 25 '11 at 18:28

This might be the most inelegant solution ever, but for most cases it can work without having to pass the variable to each function, which is something you don't want to do.

Just create a function that returns the value you need as "global", and call that function whenever you need it. Since you said you want this variable to be accessed only inside ONE php file, just place this defining function there:

function faux_global()
{
  $faux_global_var = 'This is supposed to be global';
  return $faux_global_var;
}

score 0 · Answer 3 · edited Jun 02 '19 at 14:07

I want a constant variable to be used by many functions. But it's use is only for my module and should not bother other's code. Actually I'm working on Drupal.

I don't know the requirements of a Drupal module very well, but what you describe sounds like a protected constant or variable. As protected constants do not exist, the only option is to create a protected variable. Just place all your module function code into one or multiple class(es) that have access to a protected member variable and you're fine.

class MyModule
{
    protected $variable;
    public function myFunction()
    {
        $this->$variable; # accessible only within MyModule functions.
    }
}

A private variable works as well, as long as you only use one class.

score -1 · Accepted Answer · answered Dec 25 '11 at 18:12

-1

with PHP5.2 and below, you simply can't do it. Once it's global, it's global.

but from 5.3 onwards, there is Namespacing, which allows different levels of scope.

see here: http://www.ibm.com/developerworks/opensource/library/os-php-5.3new3/index.html

answered Dec 25 '11 at 18:12

Kae Verens

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Can a global variable in my file be accessed in other file without including my php file and just by using global declaration of my variable? – user774250 Dec 25 '11 at 18:18
The answer is somehow misleading. Namespaces do not allow to limit variable scope, but deal with the name of something only. – hakre Dec 25 '11 at 21:58
@user774250: A global variable can be (ever) accessed everywhere (globally). – hakre Dec 25 '11 at 21:59
ah - damn, yes, the repliers are right. further info here: http://stackoverflow.com/questions/5287315/can-php-namespaces-contain-variables – Kae Verens Dec 25 '11 at 23:42

Limiting a global variable access to my php file only

4 Answers4