Суперглобальные переменные
$_SERVER
Предопределённые переменные
PHP Manual

# $GLOBALS

$GLOBALS — References all variables available in global scope

### Описание

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.

### Примеры

Пример #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();
?>`

Результатом выполнения данного примера будет что-то подобное:

    $foo in global scope: Example content
    $foo in current scope: local variable

### Примечания

> Замечание: 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.

> Замечание: Variable availability
> Unlike all of the other superglobals, $GLOBALS has essentially always been available in PHP.

Суперглобальные переменные
$_SERVER
Предопределённые переменные
PHP Manual