These objects are modeled using classes defined in database schemas.

The model can be emulated in languages with multiple inheritance, using abstract classes.

Another reason for using classes is to simplify the relationships of interrelated data.

We can model this notion using inner classes as follows:

Using the certification system, players will be able to customise how they play using different classes or vehicles.

Identify reusable components from existing code using classes and class libraries.

The code using such classes doesn't depend on the exact location the data is read from or is written to.

Thompson uses the term "working class" rather than "classes" throughout, to emphasize the growth of a working-class consciousness.

Using arrays, types and classes to develop highly complicated programs.

It's an object-oriented language, but instead of using classes, it has only objects and prototypes.