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

Chapter 3. Using Iterators

ES8 and earlier versions introduced new object interfaces and loops for iteration. The addition of the new iteration protocols opens up a new world of algorithms and abilities for JavaScript. We will start the chapter by introducing the symbols and various properties of the Symbol object. We will also learn how execution stacks are created for the nested function calls, their impacts, and how to optimize their performance and memory usage. Although symbols are a separate topic to iterators, we will still be covering symbols in this chapter, because to implement the iterable protocol, you need to use symbols. In this chapter, we'll cover:

  • Using symbols as the object property keys
  • Implementing the iteration protocols in objects
  • Creating and using the generator object
  • Using the for…of loop for iterating
  • The tail call optimization