Learning Node, 2nd Edition

Chapter 9. Node and ES6

Most of the examples in the book use JavaScript that has been widely available for many years. And it’s perfectly acceptable code, as well as very familiar to people who have been coding with the language in a browser environment. One of the advantages to developing in a Node environment, though, is you can use more modern JavaScript, such as ECMAScript 2015 (or ES6, as most people call it), and even later versions, and not have to worry about compatibility with browser or operating system. Many of the new language additions are an inherent part of the Node functionality.

In this chapter, we’re going to take a look at some of the newer JavaScript capabilities that are implemented, by default, with the versions of Node we’re covering in this book. We’ll look at how they can improve a Node application, and we’ll look at the gotchas we need to be aware of when we use the newer functionality.

List of Supported ES6 Functionality

I’m not covering all the ES6 functionality supported in Node—just the currently implemented bits that I’ve seen frequently used in Node applications, modules, and examples. For a list of E6 shipped features, see the Node documentation.

Strict Mode

JavaScript strict mode has been around since ECMAScript 5, but its use directly impacts on the use of ES6 functionality, so I want to take a closer look at it before diving into the ES6 features.

Strict mode is turned on when the following is added to the top of the Node application: