Are php global variables shared?

Several super global variables (superglobals) are predefined in PHP, which means that they are available in the entire scope of a script. You can use it in functions and classes without special instructions.

##PHP $GLOBAL (Recommended learning: PHP programming from entry to proficiency)

$GLOBAL is a super global variable group of PHP that can be accessed in the entire scope of a PHP script.

$GLOBAL is a global combined array containing all variables. The name of the variable is the key of the array.

The following example introduces how to use the super global variable $GLOBAL:

<?php 
$x = 75; 
$y = 25;
  
function addition() 
{ 
$GLOBALS[&#39;z&#39;] = $GLOBALS[&#39;x&#39;] + $GLOBALS[&#39;y&#39;]; 
}
  
addition(); 
echo $z; 
?>

In the above example, z is a super global variable in the $GLOBALS array, which can also be used accessed outside the function.

PHP $_SERVER

$_SERVER is a server that contains information such as header, path, script locations, etc. array. The items in this array are created by the web server. There is no guarantee that every server will offer all items; servers may ignore some, or serve items not listed here.

PHP $_REQUEST

PHP $_REQUEST is used to collect data submitted by HTML forms.

PHP $_POST

PHP $_POST is widely used to collect form data. Specify this attribute in the HTML form tag: "method="post".

PHP $_GET

PHP $_GET is also widely used to collect form data. Specify this attribute in the HTML form tag: "method="get".

$_GET can also collect data sent in the URL.

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