On Thu, Jul 22, 2010 at 2:40 AM, Ashley Sheridan <ash@xxxxxxxxxxxxxxxxxxxx>wrote: > The larger a script or class is, the more memory this uses per instance. > This is not quite true. When the script is loaded, it requires a fixed amount of memory to parse it. The larger it is, the more memory it requires. Next, the script itself is executed, running any top-level code (not in a class or global function). If that includes any require/include statements, those scripts are loaded (if necessary). If it creates objects, that takes more memory. However, the size of each instance of the class is affected only by the data it stores--not the number or length of its methods. PHP creates a single internal Class object to contain the methods, and this indeed takes memory proportional to the number of methods, but this doesn't affect the instances. Each instance stores only its instance properties such as $this->firstName. This correction aside, the advice here is spot on: split your classes based on responsibilities. The reason for this has more to do with ease of development than performance. Say you have one monster class filled with static methods. If your application uses most of those methods for each request, splitting it will have no performance benefit because both scripts will end up being loaded anyway. But if you can group the methods into logical subsystems, they will be easier to understand and work with. Peace, David
