Head First JavaScript Programming

Chapter 4. Arrays

Putting Some Order in Your Data

There’s more to JavaScript than numbers, strings and booleans. So far you’ve been writing JavaScript code with primitives—simple strings, numbers and booleans, like “Fido”, 23, and true. And you can do a lot with primitive types, but at some point you’ve got to deal with more data. Say, all the items in a shopping cart, or all the songs in a playlist, or a set of stars and their apparent magnitude, or an entire product catalog. For that we need a little more ummph. The type of choice for this kind of ordered data is a JavaScript array, and in this chapter we’re going to walk through how to put your data into an array, how to pass it around and how to operate on it. We’ll be looking at a few other ways to structure your data in later chapters but let’s get started with arrays.

Can you help Bubbles-R-Us?

Meet the Bubbles-R-Us company. Their tireless research makes sure bubble wands & machines everywhere blow the best bubbles. Today they’re testing the “bubble factor” of several variants of their new bubble solution; that is, they’re testing how many bubbles a given solution can make. Here’s their data:

Of course you want to get all this data ...