ECMAScript Language Specification, Version 11

12.5.5. The typeof Operator

4 Documented Misconceptions

ClassDefinesType

The type of an object is equivalent to the type defined by its class definition

NullAndUndefinedAreTheSame

The values null and undefined are the same

TypeofArrayIsArray

The typeof operator applied on an array returns 'array'

TypeofNullIsNull

The value null is of type 'null'