How to delete global variables in php

php method to delete global variables: 1. Open the corresponding PHP code file; 2. Find the global variable; 3. Delete the global variable through the "unset($db,$user);" method.

The operating environment of this article: Windows 7 system, PHP version 7.1, Dell G3 computer.

How to delete global variables in php?

global Only declare references to global variables in functions

php will release all resources at the end of the program, including of course variables

$Function destruction

global $db;
global $user;
unset($db,$user);

Related introduction:

Super global variables were introduced in PHP 4.1.0 and are built-in variables that are always available in all scopes.

PHP Global Variables - Superglobal Variables

Many of the predefined variables in PHP are "superglobal", which means they are available throughout the entire scope of a script. They can be accessed within a function or method without executing global $variable;.

These super global variables are:

$GLOBALS
$_SERVER
$_REQUEST
$_POST
$_GET
$_FILES
$_ENV
$_COOKIE
$_SESSION

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