note 122018 added to language.variables.scope

Using $GLOBALS inside a function you can override all references to global variables in that function with variables passed into the function as arguments. This is useful when a function does stuff to a global object but you sometimes want it to do that stuff to a different object, and you don't want to rewrite any code. For example, suppose there's a global object called $user that refers to the currently-logged-in user and a function that does stuff to that user object: <?php function example_function() { global $user; // do stuff with the object echo $user->id; } ?> Here's how you can make that function optionally do stuff to a different user object: <?php function example_function(&$user = null) { if(!isset($user)) { // if the function argument isn't provided, ... $user = $GLOBALS['user']; // ... use the global variable } // do stuff with the object echo $user->id; } ?> Example usage: <?php example_function(); // this will print the logged-in user's ID $test_user = load_user_by_id(1453); example_function($test_user); // this will print 1453 ?> ---- Server IP: 208.43.231.9 Probable Submitter: 68.190.81.78 ---- Manual Page -- http://php.net/manual/en/language.variables.scope.php Edit -- https://master.php.net/note/edit/122018 Del: integrated -- https://master.php.net/note/delete/122018/integrated Del: useless -- https://master.php.net/note/delete/122018/useless Del: bad code -- https://master.php.net/note/delete/122018/bad+code Del: spam -- https://master.php.net/note/delete/122018/spam Del: non-english -- https://master.php.net/note/delete/122018/non-english Del: in docs -- https://master.php.net/note/delete/122018/in+docs Del: other reasons-- https://master.php.net/note/delete/122018 Reject -- https://master.php.net/note/reject/122018 Search -- https://master.php.net/manage/user-notes.php