Question

This story, like most programming stories, starts with the problem of complexity. One philosophy is that complexity can be made manageable by separating it into small compartments that are isolated from each other. These compartments have ended up with the name objects.

An object is a hard shell that hides the gooey complexity inside it and instead offers us a few knobs and connectors (such as methods) that present an interface through which the object is to be used. The idea is that the interface is relatively simple and all the complex things going on inside the object can be ignored when working with it.

As an example, you can imagine an object that provides an interface to an area on your screen. It provides a way to draw shapes or text onto this area but hides all the details of how these shapes are converted to the actual pixels that make up the screen. You’d have a set of methods—for example, drawCircle —and those are the only things you need to know in order to use such an object.

These ideas were initially worked out in the 1970s and 1980s and, in the 1990s, were carried up by a huge wave of hype—the object-oriented programming revolution. Suddenly, there was a large tribe of people declaring that objects were the right way to program—and that anything that did not involve objects was outdated nonsense.

That kind of zealotry always produces a lot of impractical silliness, and there has been a sort of counter-revolution since then. In some circles, objects have a rather bad reputation nowadays.

I prefer to look at the issue from a practical, rather than ideological, angle. There are several useful concepts, most importantly that of encapsulation (distinguishing between internal complexity and external interface), that the object-oriented culture has popularized. These are worth studying.

This chapter describes JavaScript’s rather eccentric take on objects and the way they relate to some classical object-oriented techniques.

This is a book about getting computers to do what you want them to do. Computers are about as common as screwdrivers today, but they contain a lot more hidden complexity and thus are harder to operate and understand. To many, they remain alien, slightly threatening things.