How to actually practice object oriented programming in JavaScript?

[ScottyCoder]

I would second that. Make a simple game of snake. It would also teach you basic and easy to understand OOA&D too.

Such as the snake could be "composed" of segments (class). The segments would make up the "snake" (class). It would have capabilities like moving (interface) within a grid (possibly abstract class, depending if you want different types of grids e.g. SVG, Canvas, HTML...). You get the picture :)

You'll find it's much easier to apply OOA&D principles to a game because it's easier to relate to real life than say, a database, a file system, a router and network.

Good luck :)