no it isn't. javascript has types; they exist only at runtime, but they're there. it's patently false to say it's untyped. but type differences codify certain classes of differences, and it really isn't that crazy or unusual to say that the length of a vector, array, list, whatever you want to call it, isn't a difference of type. to say that there's a type difference even if the type checker disagrees just means you and the type checker are using different type systems.