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
PacktPub.com
Contributors
Preface
Index

Basics of memory


We have to understand a little about how memory works in order to appreciate the significance of SharedArrayBuffer in JavaScript. 

Think of memory as a collection of a lot of drawers in a big almirah kind of structure, where you can open a drawer and put something in it. Every drawer has its own maximum capacity.

Every drawer also has a sticker associated with it, which has a unique number on it that helps you to note down which drawer has data and which doesn't. When the time comes to access that data, you are supplied with the numbered drawer and you can take out data accordingly.

Now, let us start by understanding the basics of memory storage. Suppose I want to store a number, say, 100, in memory. First of all, we need to convert this number into binary, because that is what computers understand, and it is easy for them to store:

The preceding figure is a binary representation of the number 100 and is how it is stored in memory.

Easy! In a similar manner, we can store more...