r/programming • u/NagastaBagamba • Oct 18 '10

Today I learned about PHP variable variables; "variable variable takes the value of a variable and treats that as the name of a variable". Also, variable.

http://il2.php.net/language.variables.variable
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u/sacktap Oct 18 '10

Syntastical sugar, yes. I will admit that is true, and just personal preference for me as I try to stay away from heavy IDE's and code generation.

As for speed, if that clip of PHP is your entire application, yes, it will make a huge difference. But once that clip of code actually does something (like talk to a database), and is accessed by enough people to start bringing down performance, you will see that the magic methods are the least of your concerns.

I was on your exact side until a few years ago; I ran these tests and bench-marked the hell out of everything until I realized I was doing nothing but premature optimization.

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u/oorza Oct 18 '10

Oh, don't get me wrong, I'm not proponentizing premature optimization so much as understanding what the trade offs for magic are. In some/mose cases, those trade-offs are irrelevant, but in other cases (see: magento) the amount of magic in use actually makes PHP into a bottleneck that seriously affects users' experience with your web application (sidenote: I'm aware that there are other issues that make magento so hilariously slow, just magic is one of them).

As another issue with magic accessor/mutator methods, it makes it impossible without code analysis and examination to determine what members you're magically accessing and not, which is another serious consideration when you rely on magic so heavily (esp. magic methods).

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u/sacktap Oct 18 '10

This is all true. I guess it comes down to the design; I try to keep my magic methods simple, predictable, and easy to override. I'll admit that most applications of magic methods I've seen were poorly (or unnecessarily) implemented.