JavaScript OOP versus classical OOP

The discussion conducted so far shows how JavaScript supports the fundamental OOP principles and can be considered a true OOP language as many others. However, JavaScript differs from most other languages for certain specific features which can create some concern to the developers used to working with programming languages that implement the classical OOP.

The first of these features is the dynamic nature of the language both in data type management and object creation. Since data types are dynamically evaluated, some features of OOP, such as polymorphism, are implicitly supported. Moreover, the ability to change an object structure at runtime breaks the common sense that binds an object to a more abstract entity such as a class.

The lack of the concept of class is another big difference with the classical OOP. Of course, we are talking about the class generalization, nothing to do with the class construct introduced by ES6 that represents just a...