Modern JavaScript

Before we get into Node.js and writing code in Koa, we should take a quick look at the modern JavaScript ES6, ES7 (and beyond) syntaxes and the advantages they bring. ES6 (or ES 2015) and ES7 (or ES 2016) are major updates to the JavaScript language that brought a lot of new features and optimized the language for readability and simplicity.

Some of the key features introduced by ES6 include let, const, object destructuring, the spread operator, and so on. The async... await syntax, which is heavily used by Koa, is a new feature introduced in ES7. Some other key features introduced by ES7 are destructuring assignment (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment) and Observables (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/observe). Beyond ES6 and Es7, a lot of new features are continually being implemented in JavaScript. Embracing these new features helps to keep up with the best practices and constantly improve the quality of the code we write.

The introduction of modern syntaxes and functions have made it possible for JavaScript developers to write concise and maintainable code, without the need to sacrifice performance. On the contrary, a lot of the new features make it possible to do more things in the language. Some of these things were done in the past using external libraries that exposed helper functions. Examples of such libraries include Lodash and Underscore.js.