Essential TypeScript 5, Third Edition MEAP V04 cover
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Dear Reader,

Thank you for purchasing Essential TypeScript 5.

This is the 3rd edition of this book, and the first to be published by Manning, and I am delighted that it is ready for the MEAP process.

TypeScript is one of the most misunderstood technologies in use today. Many developers adopt TypeScript believing it to be a C#/JavaScript hybrid, given the similarity in syntax and the fact that TypeScript is produced by Microsoft.

But the reality is entirely different: TypeScript doesn’t alter the way that JavaScript works – it makes it easier to describe how JavaScript code uses data types and highlights possible problems. That may not seem like a huge benefit, but the JavaScript type system causes endless confusion and TypeScript makes it easier to write complex code that can be readily understood by others, and which has fewer bugs when it is deployed.

The link between TypeScript and JavaScript is so fundamental that this book includes a two-chapter primer that explains how the JavaScript type system works, which provides the foundation for understanding the features that TypeScript provides. Following the primer, I explain how the TypeScript development tools work, and then begin describing the TypeScript features in depth. The final part of this book shows TypeScript in context, creating the same web application in three different ways: using just TypeScript and JavaScript; using Angular; and using React.