How to tell if two JavaScript instances are of the same class type?

Question

I'm using John Resig's Simple Inheritance Class to define some classes, say:

var MyClass = Class.extend({});
var MyOtherClass = Class.extend({});

then I have some instances

var instanceA = new MyClass();
var instanceB = new MyClass();
var instancec = new MyOtherClass();

How can I determine if instanceA is of the same "type" as instanceB?

Note: I'm not asking to check if they are both a MyClass, I need to determine the class of one, and then see if the other is the same, regardless of whether they are MyClasss, MyOtherClasss or any other type.

instanceA.constructor == instanceB.constructor; (unless you re-define/delete the constructor property) — dandavis, Jul 25 '14 at 16:08

score 24 · Accepted Answer · answered Jul 25 '14 at 16:14

24

If you need to know if they are instances of the exact same class, (not subclasses of a common ancestor, etc) then this will work:

instanceA.constructor === instanceB.constructor

answered Jul 25 '14 at 16:14

Garry Shutler

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already posted as comment by @dandavis, you could have just asked him to post the answer, would have been nice. :) – nsthethunderbolt Jul 25 '14 at 16:16

How to tell if two JavaScript instances are of the same class type?

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