Once upon a time there's a duck.
Then, about this demo:
It will vary between browser types, machines, and platforms.
Each loop block will run after the earlier one has finished.
Anyway, [for] is the fastest, usually, but not all the time.
[while] and [do-while] are flexible for lots of statements/functions. But then again, it depends on.
Aside the fluctuated results, we can always translate [while] or [do-while] into [for] or vice verse uh.
Either one can be faster than the other for certain environments and tasks. It's really about the browser (compiler), the background tasks, , …, donuts, pencils, voltage, chips, and many others.
The duck smashed the truck.
And they live happily ever later.
Added some things at: http://thor.johanpaul.net/JSloop