How do we work with JavaScript?

All this is quite well, but as we mentioned before, it so happens that the JS version available most everywhere isn't ES8, but rather the earlier JS5. An exception to this is Node.js: it is based on Chrome's V8 high-performance JS engine, which already has several ES8 features available. Nonetheless, as of today, ES8 coverage isn't 100% complete, and there are features that you will miss. (Check out https://nodejs.org/en/docs/es6/ for more on Node and V8.)

So, what can you do, if you want to code using the latest version, but the available one is an earlier, poorer one? Or, what happens if most of your users may be using older browsers, which don't support the fancy features you're keen on using? Let's see some solutions for that.

If you want to be sure before using any given new feature, check out the compatibility table at https://kangax.github.io/compat-table/es6/. (See Figure 1.1). For Node.js specifically, check out http://node.green/.

Figure 1.1. - The latest versions of JS aren't yet widely and fully supported, so you'll have to check before using any of their new features