You probably meant [object Object] :) Since arrays have their own default toString implementation (its own can of worms that is the basis for JSFuck[0]), you'd have to go out of your way with Object.prototype.toString.call to get [object Array]

[0]: https://jsfuck.com/ relies on Array#toString for casting values to strings

I intentionally corrected it, because vanilla JS arrays used to behave like this in some contexts, but I'm not even sure about which ones still.

Since the "Array" is a reference to the prototype, I think it might be outdated due to changes in undefined behavior of runtimes when serializing array objects, or logging them.

I'm pretty sure that [object Array] used to be the result of logging an array at some point.

  Object.prototype.toString

  Array.prototype.join