In like 99% of all the cases, it's not. Only every few months I find a problem that is slow and refactoring it to something other than `map` shows a discernible improvement.
So it's rare.
You're right, that would further simplify it.
Omg, this looks awful.
Thanks for pointing it out!
Well, it crashes the tool but passes all the requirements:
var fn = Math.random() <= 1 ? "Date": "";