**PHP Global variables** are the user-defined variables defined on the $GLOBALS [superglobal](https://www.educative.io/answers/what-are-superglobals-in-php). A superglobal is a special PHP variable that handles tasks like storing cookies, sessions, and server information. 

> Learn more [here](https://www.educative.io/answers/what-are-superglobals-in-php).

Variables added to $GLOBALS can be accessed anywhere regardless of scope. Variables defined at the root of a script are attached to $GLOBALS by default. New variables can be attached to $GLOBALS at any point.

# Code
The code block below contains a `concatNames` function that combines a first and last name. The $first_name and $last_name variables are accessed within the function from $GLOBAL. The new variable, $full_name is attached directly to $GLOBAL.

Line 10 and 11 show that $full_name can be accessed as a normal variable or from the $GLOBALS object.






<?php
$first_name = "John";
$last_name = "Doe";
 
function concatNames() {
  $GLOBALS['full_name'] = $GLOBALS['first_name'] . " " . $GLOBALS['last_name'];
}
 
concatNames();
echo $full_name . "\n";
echo $GLOBALS['full_name'];
?>

What are PHP global variables?

PHP Global variables are the user-defined variables defined on the $GLOBALS superglobal. A superglobal is a special PHP variable that handles tasks like storing cookies, sessions, and server information.  Learn more here.  Variables added to $GLOBALS can be accessed anywhere regardless of scope. Variables defined at the root of a script are attached to $GLOBALS by default. New variables can be attached to $GLOBALS at any point. 