Classes at runtime

[Reformed]

When PHP interprets a class, does it have to evaluate every method in a class upon creating an object? For example, if I have really large class, with a lot of methods but I'm only calling one method from that class, does PHP have to go though the entire class, including every method it contains, to instantiate the object and excute the one method I'm using?

[Shrike]

You can invoke class methods statically, as long as you don't need to use member variables:

$methodresult = ClassName::Method();

If you need to use member vars then you could take a look at the Singleton design pattern.

[Reformed]

Well, I understand that. I wondering how much overhead is involved with PHP's handling of the class.

So if ClassName has say, 16 different methods in it and I only call one, does PHP have to interpret all 15 methods before it creates an instance of the one method I'm actually using? Does that make sense?

[Shrike]

PHP interprets the entire script before doing anything. If you instantiate the class you also create the a copy of the entire class (including methods) in memory.

You might want to look at splitting the class up if it's getting too heavy.

[Reformed]

I found a good (long) article about optimizing PHP and the author had this to say about method calls:

Method invocation appears to be independent of the number of methods defined in the class because I added 10 more methods to the test class (before and after the test method) with no change in performance.

You can read the full article here

[Shrike]

Interesting read. I'd be surprised if theres no difference between instantiating an empty class and one with 100 methods. Perhaps something to test 🙂

[Reformed]

Yeah, I was pretty surprised to see that.