Nicholas C. Zakas

Since promises were added to JavaScript in 2015, they have become an integral part of the language. A good understanding of how promises work is more important than ever in becoming a proficient JavaScript developer. This book begins by explaining the basic concepts behind promises, including what they are, how to use them, and how to create your own. You'll then build upon these basic concepts to learn how to chain promises together and how to respond to multiple promises at once. Once you've learned these advanced concepts, you'll move on to learn how promises work with async functions and how to track unhandled promise rejections. All of the concepts discussed are grounded in real world examples so you learn not just how to use a particular technique, but also why and when to use it. It doesn't matter if you're writing JavaScript for web browsers, Node.js, or Deno, this book will teach you everything you need to know about promises.

ECMAScript 6 represents the biggest update to the core of JavaScript in the history of the language. In Understanding ECMAScript 6, expert developer Nicholas C. Zakas provides a complete guide to the object types, syntax, and other exciting changes that ECMAScript 6 brings to JavaScript. Every chapter is packed with example code that works in any JavaScript environment so you ll be able to see new features in action. You ll learn: How ECMAScript 6 class syntax relates to more familiar JavaScript concepts What makes iterators and generators useful How arrow functions differ from regular functions Ways to store data with sets, maps, and more The power of inheritance How to improve asynchronous programming with promises How modules change the way you organize code Whether you re a web developer or a Node.js developer, you ll find Understanding ECMAScript 6 indispensable on your journey from ECMAScript 5 to ECMAScript 6.

If you've used a more traditional object-oriented language, such as C++ or Java, JavaScript probably doesn't seem object-oriented at all. It has no concept of classes, and you don't even need to define any objects in order to write code. But don't be fooled JavaScript is an incredibly powerful and expressive object-oriented language that puts many design decisions right into your hands. In The Principles of Object-Oriented JavaScript, Nicholas C. Zakas thoroughly explores JavaScript's object-oriented nature, revealing the language's unique implementation of inheritance and other key characteristics. You'll learn: The difference between primitive and reference values What makes JavaScript functions so unique The various ways to create objects How to define your own constructors How to work with and understand prototypes Inheritance patterns for types and objects The Principles of Object-Oriented JavaScript will leave even experienced developers with a deeper understanding of JavaScript. Unlock the secrets behind how objects work in JavaScript so you can write clearer, more flexible, and more efficient code.

When you're writing code alone, you have a lot of leeway. But when you start writing code as part of a team, you need to think harder about the decisions you make. This book will help you do that. When you write code in a team setting, will other developers be able to understand what you did? Did you organize your code in such a way that it's easy to adapt and extend? Will your code survive once you're gone? Maintainable JavaScript doesn't just recommend a set of guidelines, it examines guidelines being used and recommended by others in the industry, so you get a feel for what's common in well-run JavaScript projects. Save a copy of this book now. It's the only resource that focus solely on JavaScript conventions.

If you're like most developers, you rely heavily on JavaScript to build interactive and quick-responding web applications. The problem is that all of those lines of JavaScript code can slow down your apps. This book reveals techniques and strategies to help you eliminate performance bottlenecks during development. You'll learn how to improve execution time, downloading, interaction with the DOM, page life cycle, and more. Yahoo! frontend engineer Nicholas C. Zakas and five other JavaScript experts -- Ross Harmes, Julien Lecomte, Steven Levithan, Stoyan Stefanov, and Matt Sweeney -- demonstrate optimal ways to load code onto a page, and offer programming tips to help your JavaScript run as efficiently and quickly as possible. You'll learn the best practices to build and deploy your files to a production environment, and tools that can help you find problems once your site goes live. * Identify problem code and use faster alternatives to accomplish the same task * Improve scripts by learning how JavaScript stores and accesses data * Implement JavaScript code so that it doesn't slow down interaction with the DOM * Use optimization techniques to improve runtime performance * Learn ways to ensure the UI is responsive at all times * Achieve faster client-server communication * Use a build system to minify files, and HTTP compression to deliver them to the browser