Using namespaces
__NAMESPACE__
Namespaces
PHP Manual

## Global space

Without any namespace definition, all class and function definitions are placed into the global space - as it was in PHP before namespaces were supported. Prefixing a name with :: will specify that the name is required from the global space even in the context of the namespace.

Example#1 Using global space specification

`<?php
namespace A::B::C;
/* This function is A::B::C::fopen */
function fopen() {
/* ... */
$f = ::fopen(...); // call global fopen
return $f;
}
?>`

Using namespaces
__NAMESPACE__
Namespaces
PHP Manual