Working online

There are some more online tools that you can use to test out your JS code. Check out JSFiddle (at https://jsfiddle.net/), CodePen (at https://codepen.io/), or JSBin (at http://jsbin.com/), among others. You may have to specify whether to use Babel or Traceur; otherwise, newer JS features will be rejected. See an example of JSFiddle in Figure 1.5:

Figure 1.5 - JSFiddle lets you try out ES8 code (plus HTML and CSS) without requiring any further tools