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Asked: 2026-05-10T17:08:03+00:00

Is it a problem if you use the global keyword on variables you don’t

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Is it a problem if you use the global keyword on variables you don’t end up using? Compare:

function foo() {     global $fu;     global $bah;     if (something()) {         $fu->doSomething();     } else {         $bah->doSomething();     } }  function bar() {     if (something()) {         global $fu;         $fu->doSomething();     } else {         global $bah;         $bah->doSomething();     } }

I’m quite aware that using the second method makes maintaining this code much harder, and that it’s generally preferred to put all your globals at the start of functions, so: Ignoring the difference in maintainability and code-styling of the two functions, is there a difference between these two in terms of overhead?

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  1. If there is, it won’t be (humanly) measurable, unless you are literally calling this function millions of times. And even if it was a recursive function with that property, I still wouldn’t use your second method for the maintainability aspects you already brought up.

    Edit: For arguments sake, I actually went and benchmarked this, and bar() ended up slower by 0.1s over one million calls. Which means performance wise, you still have a reason to use the cleaner version.

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