It is commonly taught that global variables are “relics” of poor practice by beginning programmers, and therefore should be avoided. However, like the infamous <table> tag, globals still perform a function that is required in programming. The fact is that we need access to our objects from all manner of locations.

Take PHP for example, no self-respecting programmer would admit to using the global keyword to fetch object instances. The main reason is that a global instance could be accidentally overwritten or changed the same way as normal variable. You could say that by using “global” you are allowing read & write access to the object it’s self which might lead to problems down the road.

To stop this bad practice, programmers begin a Holy War against globals when all that was really needed was to remove write access to the object. Because of this new ways to keep objects global began emerging - however, at their basic level they are nothing more than alternative methods of storing and fetching globals.

//EVIL Global Variables
global $class;
$class->method();

//Global Static classes
CLASS::method();

//Global throughout object instance (MVC Frameworks)
$this->class->method();

//Global from static singlton instances
$class = CLASS::instance();
$class->method();

It is time to start correctly explaining global objects in a balanced way. Not in miss-placed confusion about the usefulness of accessing values where they are needed. While I don’t recommend we start using “global” again, we do need to represent the concepts correctly.