Language Features Supported in ES5, ES6, ES7, ES8, and ES9
Before we dive into the depths of these amazing language features, let's take a look at the different versions of JavaScript. Currently, most websites that you regularly come across that still support legacy browsers use ES5. As of 2019, many mainstream browsers have already added support for ES6. Later versions will only have minimal browser support. Since we will be running and testing our code in a Node.js runtime, we don't have to worry about version compatibility as long as we are using the latest LTS (long term support) version of Node.js. Regarding the materials that will be used in this chapter, here is a breakdown of the minimum ES version your runtime needs to support:
Figure 7.1: Minimum required ES version
In this chapter, we won't be switching runtimes, but in the future, it is best to check the language support on the runtime you are going to be developing for before getting...