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

Working with SessionStorage


Session storage is just like local storage, with the exception that session storage is not persistent. That means whenever you close even the tab that sets the session storage, your data will be lost.

A case where session storage could be useful could be when you have an Ajax-based website that loads everything dynamically. You want to create a state-like object, which you can use to store the state of the interface so that, when a user returns to a page they have already visited, you can easily restore the state of that page.

Let's now quickly go over all the methods of session storage.

Creating a session storage entry

To create a key-value pair inside the sessionStorage object, you can use the setItem method, similar to the localStorage object. Just like localStorage, sessionStorage is also a synchronous API, so you can be sure that you'll immediately have access to whatever values you're storing.

Adding an item to session storage is just like working with local...