PHP Global Variable Declaration
Unlike local variables, a global variable can be accessed in any part of the program. Global Variable Declaration in PHP is quite simple, if we want a variable to be accessible from within a function, we can use the global keyword.
Global Variable can be accessed anywhere in our script, whether inside or outside a function. In order to modify a global variable, it must be explicitly declared to be global in the function in which it is to be modified.
Superglobals
Superglobals are built-in variables which are always available in all scopes throughout the script and hence it is not required to declare global $variable to access them within functions or methods.
These superglobal variables are:
1. $GLOBALS
It references all variables available in global scope.
PHP $GLOBALS Example
This will produce following result
2. $_SERVER
It is an array which contains information like headers, paths,and script locations.
PHP $_SERVER Example
This will produce following result
3. $_GET
It is an associative array of variables passed to the current script through URL parameters.
PHP $_GET Example
Suppose the user has made an entry https://example.com/?myname=Bill
This will produce following result
4. $_POST
It is an associative array of variables passed to the current script through HTTP POST method.
PHP $_POST Example
Suppose the user has made an entry posted hostname = Jim
This will produce following result
5. $_COOKIE
It is an associative array of variables passed to the current script through HTTP Cookies.
PHP $_COOKIE Example
Suppose the "myname" cookie has already been set
This will produce following result
