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

Cookies versus local storage

By now, you may have observed that cookies and local storage serve almost completely different purposes. The only thing they have in common is that they store data. The following is a brief comparison of cookies and local storage:


Local storage

Cookies are transferred to a server on every request automatically by the browser

To transfer local storage data to a server, you need to manually send an Ajax request or send it through hidden form fields

If data needs to be accessed and read both by the client and server, use cookies

If the data needs to be accessed and read only by the client, use local storage

Cookies can have an expiration date, after which they are automatically deleted

Local storage provides no such expiration date feature; it can only be cleared by JavaScript

The maximum size of a cookie is 4 KB

The maximum size of local storage depends on the browser and platform, but it is usually around 5 MB per domain