PHP $GLOBALS
$GLOBALS is an array that contains all global
variables.
Global Variables
Global variables are variables that can be accessed from any scope.
Variables of the outer most scope are automatically global variables, and can be used by any scope, e.g. inside a function.
To use a global variable inside a function you have to either define them as global with
the global keyword, or refer to them by using the
$GLOBALS syntax.
Example
Refer to the global variable $x inside a function:
$x = 75;
function myfunction() {
echo $GLOBALS['x'];
}
myfunction()
This is different from other programming languages where global variables are available without specifically referring to them as global.
Example
In PHP you get nothing (or an error) when referring to a global variable without the $GLOBALS syntax:
$x = 75;
function myfunction() {
echo $x;
}
myfunction()
You can also refer to global variables inside functions by defining them as global with the global keyword.
Example
Define $x as global inside a function:
$x = 75;
function myfunction() {
global $x;
echo $x;
}
myfunction()
Create Global Variables
Variables created in the outer most scope are global variables either if they are created using the
$GLOBALS syntax or not:
Variables created inside a function belongs only to that function, but you can create global variables inside a function
by using the $GLOBALS syntax:
Example
Create a global variable from inside a function, and use it outside of the function:
function myfunction() {
$GLOBALS["x"] = 100;
}
myfunction();
echo $GLOBALS["x"];
echo $x;
