JavaScript: Difference Between typeof, instanceof, constructor property

• typeof return the type of the object, but array, object, date, regex, etc all just return "object". [see “typeof” Operator]
• instanceof checks if a object is in the Prototype Chain of a function's property "prototype"'s value. [see instanceof Operator]
• Property key "constructor" is meant to return the function that created the object.

TIP: You shoud avoid using any of them, because they are not reliable.

Instead, check directly what you are looking for, by:

• Check for parent object. [see Get/Set Prototype]
• Check for the exact “subtype” of a object. [see Determine Type of Object]
• Check for the exact property, own or inherited. [see Check Property Existence]