Why does the following return false?
Object.prototype instanceof Object
Why does the following return false?
Object.prototype instanceof Object
Because it basically asks whether Object.prototype
does inherit from Object
's .prototype
object: It does not.
a instanceof b
is equivalent to b.prototype.isPrototypeOf(a)
- it tests whether b.prototype
is in the prototype chain of a
. In your case, it is not in the chain, because it is the start of the chain itself. isPrototypeOf
is not reflexive.
Referencing MDN:
The
instanceof
operator tests whether an object has in its prototype chain theprototype
property of a constructor.