Book Image

Learn ECMAScript - Second Edition

By : MEHUL MOHAN, Narayan Prusty
Book Image

Learn ECMAScript - Second Edition

By: MEHUL MOHAN, Narayan Prusty

Overview of this book

Learn ECMAScript explores implementation of the latest ECMAScript features to add to your developer toolbox, helping you to progress to an advanced level. Learn to add 1 to a variable andsafely access shared memory data within multiple threads to avoid race conditions. You’ll start the book by building on your existing knowledge of JavaScript, covering performing arithmetic operations, using arrow functions and dealing with closures. Next, you will grasp the most commonly used ECMAScript skills such as reflection, proxies, and classes. Furthermore, you’ll learn modularizing the JS code base, implementing JS on the web and how the modern HTML5 + JS APIs provide power to developers on the web. Finally, you will learn the deeper parts of the language, which include making JavaScript multithreaded with dedicated and shared web workers, memory management, shared memory, and atomics. It doesn’t end here; this book is 100% compatible with ES.Next. By the end of this book, you'll have fully mastered all the features of ECMAScript!
Table of Contents (18 chapters)
Title Page

Working with numbers

ES6, ES2016 (ES7), and ES2017 (ES8) bring new ways of creating numbers and new properties to the Number object to make working with numbers easier. The Number object was enhanced greatly in ES6 to make it easier to create mathematically rich applications and prevent the common misconceptions that caused the errors.

The binary notation

Earlier, there was no native way to represent numeric constants as binary. But now, you can prefix numeric constants using the 0b token to make JavaScript interpret them as binary. Here is an example:

let a = 0b00001111;
let b = 15;
console.log(a === b);

The output is as follows:


Here, 0b00001111 is a binary representation of 15, base 10 decimal.

The octal notation

The octal notation is a number system where we use only eight digits, that is, from 0 to 7. You can represent a number in octal format with JavaScript if you like.

Earlier, to represent a numeric constant as octal, we needed to prefix the numeric constant using...