text: what takes less resources? php classes or functions for a high volume app? i would like to know what takes less resources? php classes or php functions? i can take a reasonable guess not having looked at how it's implemented...  once the object exists there will be almost no difference. remember, a class is simply a collection of functions that have protected access to a group of variables. the only real drawback in oo languages is setting up this access for new objects, but these days it's hardly worth the mention. inheritance, and the heirarchy lookup may, but it's extremely unlikely, make some slight difference.  at the end of the day, you need to store in variables what you need to store. putting them in objects is simply more convenient in so many ways. you pay a tiny bit in performance for that, but you probably use less developer resources (if they count here).