Conceptual Doubt : Why is Javascript not an OOP?

The challenge I am on ( ) clearly states that " the class syntax is just a syntax, and not a full-fledged class based implementation of object oriented paradigm, unlike in languages like Java, or Python, or Ruby etc."

MDN Web Docs state " JavaScript classes, introduced in ECMAScript 2015, are primarily syntactical sugar over JavaScript’s existing prototype-based inheritance. The class syntax does not introduce a new object-oriented inheritance model to JavaScript."

I have some basic understanding of OOP due to beginner knowledge of Java. I would like a bit of clarity here. Why is JS not an OOP? I read somewhere that JS is “Prototype based Programming (PBP)”. Another medium article suggested it is an OOP (link :

At this point I am very confused, and would really appreciate some clarity on the matter.

  1. Is JS OOP or PBP? Why?
  2. Optional : how are these different?

Thank you.

I’d recommend doing some googling with terms like “classical inheritance vs prototypical inheritance” and checking out some of the results until you find one that uses terminology that you’re comfortable with.

This article looks like it might be a good place to start, but there are others that go more in-depth.

I guess it depends on who you ask if it is “real” OOP or not.

The OOP model (prototypal inheritance) in JS was inspired by Self. Here is a video interview with Brendan Eich, it’s a bit old now but it touches on some of the influences and history.