PHP/global

From DocForge

global is a PHP construct which makes a global variable available in local scope. A variable is initialized globally when it's first used outside of any function or class. Global variables can also be accessed with the superglobal array $GLOBALS.

PHP superglobal variables are always available in every scope. They do not require use of the global keyword.

[edit] Example

$string = 'abc';
 
function foo() {
  $string = 'def';
  /* Local variable $string now has the value 'def' 
     while global variable $string retains the value 'abc'.  */
}
 
function bar() {
  global $string;
 
  $string = 'def';     // Global variable $string now has the value 'def'
}
 
foo();
echo $string;  // Outputs 'abc'
bar();
echo $string;  // Outputs 'def';

[edit] See Also

• PHP/$GLOBALS
• PHP/Superglobals