To get the most out of this book

Although it's not strictly required, it'll be great if you know a little about HTML/CSS and a little about how to create basic web pages using it.

You should be familiar with a modern browser (Chrome or Firefox is preferred) on a desktop/laptop.

To get the most out of this book, don't just read the book alone; keep other study sources open and implement as many of the demo and example codes as you can.

Download the example code files

You can download the example code files for this book from your account at www.packtpub.com. If you purchased this book elsewhere, you can visit www.packtpub.com/support and register to have the files emailed directly to you.

You can download the code files by following these steps:

1. Log in or register at www.packtpub.com.
2. Select the SUPPORT tab.
3. Click on Code Downloads & Errata.
4. Enter the name of the book in the Search box and follow the onscreen instructions.

Once the file is downloaded, please make sure that you unzip or extract the folder using the latest version of:

• WinRAR/7-Zip for Windows
• Zipeg/iZip/UnRarX for Mac
• 7-Zip/PeaZip for Linux

The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/Learn-ECMAScript-Second-Edition. In case there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

Conventions used

There are a number of text conventions used throughout this book.

CodeInText: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "Look carefully, we are not executing counter() again and again."

A block of code is set as follows:

let myCounter = counter(); // returns a function (with count = 1)
myCounter(); // now returns 2
myCounter(); // now returns 3

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

var ob1 = {
   prop1 : 1,
    prop2 : {
        prop2_1 : 2 
    }
};
Object.freeze( ob1 );

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "However, you can specify the distance to move, that is history.go(5); is equivalent to the user hitting the forward button in the browser five times."

Warnings or important notes appear like this.

Tips and tricks appear like this.