[thdc]

I believe this is technically inaccurate; while Javascript groups most of the number values under, well, "number", modern underlying implementations may resort to perform integer operations when they recognize it is possible. There are also a couple hacks you can do with bit operations to "work" with integers, although I don't remember them off the top of my head - typically used for truncating and whatnot and was mainly a performance thing.

Also there are typed arrays and bigints if we can throw those in, too.

[saagarjha]

The way runtimes optimize arithmetic is an implementation detail and must conform to IEEE-754.

[thdc]

Fair point, I have been taking smis for granted