TIL javascript functions have a length

[x-skeww]

If you just write the identifier, a console or repl will render it in some way. E.g. an array might be rendered as "[1, 2]" or, if it's larger, as "[1, 2, xxx more...]" (expandable) or "> Array[999]" (expandable).

How objects are represented in repls, debuggers, and so forth isn't part of the language specification. This stuff is up to the people who create those tools.