PHP global in functions

Question

What is the utility of the global keyword?

Are there any reasons to prefer one method to another?

• Security?
• Performance?
• Anything els

Answer 1

Dont hesitate from using global keyword inside functions in PHP. Especially dont take people who are outlandishly preaching/yelling how globals are 'evil' and whatnot.

Firstly, because what you use totally depends on the situation and problem, and there is NO one solution/way to do anything in coding. Totally leaving aside the fallacy of undefinable, subjective, religious adjectives like 'evil' into the equation.

Case in point :

Wordpress and its ecosystem uses global keyword in their functions. Be the code OOP or not OOP.

And as of now Wordpress is basically 18.9% of internet, and its running the massive megasites/apps of innumerable giants ranging from Reuters to Sony, to NYT, to CNN.

And it does it well.

Usage of global keyword inside functions frees Wordpress from MASSIVE bloat which would happen given its huge ecosystem. Imagine every function was asking/passing any variable that is needed from another plugin, core, and returning. Added with plugin interdependencies, that would end up in a nightmare of variables, or a nightmare of arrays passed as variables. A HELL to track, a hell to debug, a hell to develop. Inanely massive memory footprint due to code bloat and variable bloat too. Harder to write too.

There may be people who come up and criticize Wordpress, its ecosystem, their practices and what goes on around in those parts.

Pointless, since this ecosystem is pretty much 20% of roughly entire internet. Apparently, it DOES work, it does its job and more. Which means its the same for the global keyword.

Another good example is the "iframes are evil" fundamentalism. A decade ago it was heresy to use iframes. And there were thousands of people preaching against them around internet. Then comes facebook, then comes social, now iframes are everywhere from 'like' boxes to authentication, and voila - everyone shut up. There are those who still did not shut up - rightfully or wrongfully. But you know what, life goes on despite such opinions, and even the ones who were preaching against iframes a decade ago are now having to use them to integrate various social apps to their organization's own applications without saying a word.

......

Coder Fundamentalism is something very, very bad. A small percentage among us may be graced with the comfortable job in a solid monolithic company which has enough clout to endure the constant change in information technology and the pressures it brings in regard to competition, time, budget and other considerations, and therefore can practice fundamentalism and strict adherence to perceived 'evils' or 'goods'. Comfortable positions reminiscent of old ages these are, even if the occupiers are young.

For the majority however, the i.t. world is an ever changing world in which they need to be open minded and practical. There is no place for fundamentalism, leave aside outrageous keywords like 'evil' in the front line trenches of information technology.

Just use whatever makes the best sense for the problem AT HAND, with appropriate considerations for near, medium and long term future. Do not shy away from using any feature or approach because it has a rampant ideological animosity against it, among any given coder subset.

They wont do your job. You will. Act according to your circumstances.