Installing an editor

The easiest way for you to learn D3 is by playing around with the examples, and see what happens when you change part of the code. So when you're reading through this book, looking at the examples it is probably best to do this while sitting at your computer, and running and modifying the examples while you read. Since D3 is just plain old JavaScript and CSS (or SCSS, as we'll explain in a later chapter), all you need to edit the examples from this book is a text editor. However, it is easier to use a text editor that understands JavaScript. If you haven't got a preferred one installed, the following text editors are good for working with JavaScript:

• Sublime: This is one of the most popular editors for editing JavaScript (and other languages for that matter) and it provides builds for all major platforms. Sublime is a commercial product, but provides an evaluation copy you can use for free. You can download Sublime from here: https://www.sublimetext.com.
• Notepad ++: This is a Windows-only editor and a great choice when you're running a MS Windows environment. Notepad++ is an open source editor and can be easily extended with a number of plugins. While Notepad++ doesn't support JavaScript out of the box, it can be easily extended through the use of plugins. Notepad++ can be downloaded from here: https://notepad-plus-plus.org/. A good JavaScript plugin for Notepad++ can be found here: http://www.sunjw.us/jstoolnpp/.
• Atom: A final great cross-platform editor is Atom (from the guys behind GitHub). Atom is an editor that can be easily extended with plugins to provide a very good development environment. Atom is open source, and you can use it without any costs. Atom can be downloaded from here: https://atom.io/. A good plugin that provides additional JavaScript support can be added by installing the language-JavaScript package.

The aforementioned editors have great JavaScript support (or it can be added by using a couple of plugins). The following figure shows how Atom highlights and provides JavaScript support:

Besides editors that support JavaScript, there are also a number of Integrated Development Environments (IDEs) you can use to edit JavaScript. These provide a lot of additional functionality for testing, running, and debugging your code (which we won't touch upon in this book), and also provide a somewhat better JavaScript editing experience. A couple of good IDEs, which have a free or community edition that you can use, are listed as follows:

• WebStorm: This is a great JavaScript IDE (and anything else web related) from IntelliJ. WebStorm is provided in a community edition and a commercial one. For developing JavaScript, the community edition provides all the features that you need. You can get the community edition from here: https://www.jetbrains.com/webstorm/.
• Visual Studio: If you're on a MS Windows system, you might also have a look at the Visual Studio Community edition. It provides JavaScript support out of the box. The Visual Studio Community edition is free to use and can be found here: https://beta.visualstudio.com/vs/community/.

My personal opinion is that if you want to use a simple text editor, you should go for either Sublime or Atom, and if you want to go the IDE way, I'd pick WebStorm.

The following screenshot, for example. shows how WebStorm provides code completion for JavaScript:

But, once again, every text editor can be used, since we're just editing standard text files. If you haven't installed an editor yet, now is a good time, since in the next section we'll explain how to get the sources for this book and set up a local web server so you can run the samples.