Which in turn led V8 to invent TheHole[1], a true unset value, as an implementation detail (unavailable to the user). Honestly, it seems to me that pre-strict-

Which in turn led V8 to invent TheHole[1], a true unset value, as an implementation detail (unavailable to the user). Honestly, it seems to me that pre-strict-mode JavaScript actually made a fair attempt at making "undefined" a genuine missing value, except that then implied semantics people disliked, like an undefined variable reference having the value of "undefined" instead of being an error. Lua seems mostly OK having an actual nil, though. (There is admittedly some gnarliness, like a vararg function f being able to distinguish f(1,2,nil) from f(1,2).) [1] https://stackoverflow.com/q/61420580 https://stackoverflow.com/q/61420580