JS.next: A Manager's Guide

Chapter 3. Features Explained

ECMAScript 6 contains a large bundle of new features for programmers to explore, bringing different pieces to different projects.

Arrow Functions

When JavaScript programmers talk about what this means in JavaScript, you may feel like you’re watching “Who’s on First?” For those who are new to JavaScript, understanding what this is can often prove difficult.

What better way to provide clarity than to add yet another meaning for this? Arrow functions are a new syntax that allow developers to manage their scope differently than before, providing yet another value for this.

While that may sound confusing, arrow functions will help make JavaScript code more readable. When using arrow functions, your code reads the same way that it will execute. The same cannot be said for all usages of this. Such functionality will help make JavaScript code more readable and predictable for developers, which translates into easier maintainability.

In addition to helping developers understand what this is, arrow functions have some syntactic sugar that allows you to opt-out of using the function and return syntax in your functions.

Let, Const, and Block Functions

Prior to the ES6 release, each time you declared a new variable, you used the keyword var. There were no alternate keywords to define a variable. Starting with the ES6 release, you will now have two additional constructs for defining new variables: const and let.

Using const makes your variables a constant value. Variables ...