Intro to the Objective-C Runtime(mikeash.com)

http://www.mikeash.com/?page=pyblog/friday-qa-2009-03-13-intro-to-the-objective-c-runtime.html

1 comments

Really nice, concise summary. The importance of "isa" cannot be overstated. It's the key to Objective C's dynamic nature. It's sort of fallen out of style now, but it used to be common practice to do some really interesting stuff with "isa-swizzling" (these days there's API that replaces most of the old hacks/tricks).