I personally think that all these bad coding practices (mutating an object in getRect, using two arrays of primitives instead of arrays of objects, and avoiding enums) will cost the app more than aiding it. Good code should trump performance if you’re working in a team and want to add functionality to the app in the future. If it’s hard to understand the code you’re writing because you optimized it, then it’ll just become more and more difficult to improve the app in the future.

But that’s just me after reading “Clean Code.” I would love to hear what the developers at Google think.