Learning TypeScript: Enhance Your Web Development Skills Using Type-Safe JavaScript

From the Preface

Who Should Read This Book

If you have an understanding of writing JavaScript code, can run basic commands in a terminal, and are interested in learning about TypeScript, this book is for you.

Maybe you’ve heard TypeScript can help you write a lot of JavaScript with fewer bugs (true!) or document your code well for other people to read (also true!). Maybe you’ve seen TypeScript show up in a lot of job postings, or in a new role you’re starting.

Whatever your reason, as long as you come in knowing the fundamentals of JavaScript—variables, functions, closures/scope, and classes—this book will take you from no TypeScript knowledge to mastering the fundamentals and most important features of the language.

By the end of this book, you will understand:

• The history and context for why TypeScript is useful on top of “vanilla” JavaScript
• How a type system models code
• How a type checker analyzes code
• How to use development-only type annotations to inform the type system
• How TypeScript works with IDEs (Integrated Development Environments) to provide code exploration and refactoring tools

And you will be able to:

• Articulate the benefits of TypeScript and general characteristics of its type system.
• Add type annotations where useful in your code.
• Represent moderately complex types using TypeScript’s built-in inferences and new syntax.

TypeScript is a wildly popular language in both industry and open source: