Refactoring JavaScript

Chapter 7. Refactoring Functions and Objects

In the previous chapter, we started a project of creating a Naive Bayes Classifier (or NBC, for short). We’ve made improvements, but nothing so far really got to the heart of refactoring our functions and objects.

That’s what this chapter is all about.

Is Object-Oriented Programming Still Relevant in JavaScript?

In this and the next two chapters, we’re working with OOP. In some JavaScript styles, OOP is deemphasized in favor of functional programming. But beyond the practical reason of understanding OOP in JavaScript to support legacy projects, JavaScript’s OOP capabilities are still being expanded through the TC39 committee that decides on features for JavaScript.

It’s reasonable to have a personal preference for your own coding, but if your goal is to understand modern JavaScript, as of this writing, both FP and OOP are still being actively developed. With no clear “winner” at this point, it makes sense to learn about both.

The Code (Improved)

In case you skimmed over the last chapter or missed a step somewhere, here is the version we ended up with:

function fileName(){
  var theError = new Error("here I am");
  return theError.stack.match(/\/(\w+\.js)\:/)[1];
};
console.log(`Welcome to ${fileName()}!`);
var easy = 'easy';
var medium = 'medium';
var hard = 'hard';

imagine = ['c', 'cmaj7', 'f', 'am', 'dm', 'g', 'e7'];
somewhereOverTheRainbow = ['c', 'em', 'f', 'g', 'am'];
tooManyCooks = ['c', 'g', 'f'];
iWillFollowYouIntoTheDark ...