We’ve often gone about the run-around method to find out how many bytes a particular class or package of Actionscript files adds to a compiled swf. In the pre CS4 days (unless there was something of which we were unawares) we often created a new AS3 fla, imported and declared only the classes to be tested, and then compared the swf filesize to that of an empty swf. Not a terribly friendly method.

I haven’t seen a better method documented anywhere. Though I’ve recently found that Flash CS4 will include a list of compiled classes and their corresponding byte counts when using Generate Size Report. The trick, however, is that you also have to use the publish settings to automatically export a swc.

Here’s an example of a list of compiled classes produced when both “Generate size report” and “Export SWC” are checked:

Of course this could have been expected. A swc is just a zipped up swf and catalog.xml, listing all the compiled classes in the swf. I’m not sure why Flash doesn’t have a better system (and a more obvious reporting system) in the first place, but this hidden perk certainly reinforces the sensical quirkiness of the IDE we’ve all come to love over the years. The more you love the quirks, the more the IDE will love you back.