JavaScript: The New Toys

Introduction

The book «JavaScript: The New Toys» (author T.J. Crowder, 2020, 668 pages) is not another introduction to the language, but a deep dive into the evolution of JavaScript, starting from the ES2015 (ES6) standard and ending with the latest innovations of ES2020. The author, a well-known developer and member of the TC39 committee, offers the reader not just a list of new features, but an understanding of how and why they appeared, and how to apply them correctly in practice.

What this book is about

The book is structured as a guide to JavaScript's "new toys." Each chapter is dedicated to a specific feature or group of features: arrow functions, classes, promises, async/await, Map, Set, Symbol, Proxy, Reflect, modules, iterators, generators, typed arrays, BigInt, the global object globalThis, and much more. Special attention is paid not only to syntax but also to internal mechanisms, performance, and pitfalls.

Who this book is for

The book is intended for practicing developers who already write in JavaScript (possibly an older version) and want to master the modern standard. It will be useful for both frontend developers and backend developers using Node.js. Beginners just starting to learn JS may find the book difficult — it's better to first master the basics using another textbook.

What the reader will learn

• Arrow functions — not just syntax, but differences from regular functions (lexical this, no arguments object).
• Classes — syntactic sugar over prototypes, inheritance, static methods, private fields.
• Promises and async/await — a complete understanding of asynchronous programming, chaining, error handling.
• Iterators and generators — how for...of, spread, yield work, and how to create your own iterable objects.
• Map, Set, WeakMap, WeakSet — when and why to use them instead of objects and arrays.
• Symbol — unique identifiers, built-in symbols (Symbol.iterator, etc.).
• Proxy and Reflect — intercepting operations on objects, metaprogramming.
• ES Modules — import/export, dynamic imports, differences from CommonJS.
• Typed arrays and ArrayBuffer — working with binary data.
• BigInt — working with arbitrary precision integers.
• globalThis — universal access to the global object in any environment.
• New methods for strings, arrays, objects — includes, flat, flatMap, Object.fromEntries, etc.

Strengths

• Depth and authority — the author participates in the development of the standard, so the explanations are accurate and reflect the real motives behind decisions.
• Practical focus — every example can be run in Node.js or a browser; the code is current and tested.
• Structure — the book is divided into logical blocks; you can read selectively if you need to understand a specific topic.
• Honesty — the author is not afraid to point out the shortcomings and limitations of new features, warning about common mistakes.
• Relevance — at the time of release (2020), the book covers all key innovations, many of which remain standard today.

Who it is recommended for

The book will be useful for anyone who wants to transition from "old" JavaScript (ES5) to a modern coding style. I especially recommend it to developers using React, Vue, Angular, or Node.js — understanding new language features directly improves code quality and performance. If you are already superficially familiar with ES6, the book will help fill in the gaps and teach you many nuances.

Overall, «JavaScript: The New Toys» is a must-read for any serious JavaScript developer who wants to