Superglobals
As of PHP 5.4 $GLOBALS is now initialized just-in-time. This means there now is an advantage to not use the $GLOBALS variable as you can avoid the overhead of initializing it. How much of an advantage that is I'm not sure, but I've never liked $GLOBALS much anyways.
$GLOBALS
(PHP 4, PHP 5)
$GLOBALS — References all variables available in global scope
Description
An associative array containing references to all variables which are currently defined in the global scope of the script. The variable names are the keys of the array.
Examples
Example #1 $GLOBALS example
<?php
function test() {
$foo = "local variable";
echo '$foo in global scope: ' . $GLOBALS["foo"] . "\n";
echo '$foo in current scope: ' . $foo . "\n";
}
$foo = "Example content";
test();
?>
The above example will output something similar to:
$foo in global scope: Example content $foo in current scope: local variable
Notes
Note:
This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. There is no need to do global $variable; to access it within functions or methods.
Note: Variable availability
Unlike all of the other superglobals, $GLOBALS has essentially always been available in PHP.
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User Contributed Notes
$GLOBALS - [5 notes]
therandshow at gmail dot com ¶
1 year ago
bkilinc at deyta dot net ¶
27 days ago
I prefer accessing globals through static function calls. Source code looks better; I use glb::get('myglobalvar') instead of $GLOBALS['myglobalvar']. This gives me full control over global access, which can be the source of problems in practice.
class glb
{
static public function set($name, $value)
{
$GLOBALS[$name] = $value;
}
static public function get($name)
{
return $GLOBALS[$name];
}
}
$myglobalvar = 'Hello, World !';
function myfunction()
{
$val = glb::get('myglobalvar');
echo "$val\n";
glb::set('myglobalvar', 'hi, again :)');
$val = glb::get('myglobalvar');
echo "$val\n";
}
myfunction();
ravenswd at yahoo dot com ¶
4 years ago
Keep in mind that $GLOBALS is, itself, a global variable. So code like this won't work:
<?php
print '$GLOBALS = ' . var_export($GLOBALS, true) . "\n";
?>
This results in the error message: "Nesting level too deep - recursive dependency?"
Gratcy ¶
11 months ago
this is technique that i always did for configuration file..
<?php
$conf['conf']['foo'] = 'this is foo';
$conf['conf']['bar'] = 'this is bar';
function foobar() {
global $conf;
var_dump($conf);
}
foobar();
/*
result is..
array
'conf' =>
array
'foo' => string 'this is foo' (length=11)
'bar' => string 'this is bar' (length=11)
*/
?>