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The TypeScript Workshop

The TypeScript Workshop

By : Ben Grynhaus , Jordan Hudgens , Rayon Hunte , Matt Morgan , Wekoslav Stefanovski
4.7 (19)
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The TypeScript Workshop

The TypeScript Workshop

4.7 (19)
By: Ben Grynhaus , Jordan Hudgens , Rayon Hunte , Matt Morgan , Wekoslav Stefanovski

Overview of this book

By learning TypeScript, you can start writing cleaner, more readable code that’s easier to understand and less likely to contain bugs. What’s not to like? It’s certainly an appealing prospect, but learning a new language can be challenging, and it’s not always easy to know where to begin. This book is the perfect place to start. It provides the ideal platform for JavaScript programmers to practice writing eloquent, productive TypeScript code. Unlike many theory-heavy books, The TypeScript Workshop balances clear explanations with opportunities for hands-on practice. You’ll quickly be up and running building functional websites, without having to wade through pages and pages of history and dull, dry fluff. Guided exercises clearly demonstrate how key concepts are used in the real world, and each chapter is rounded off with an activity that challenges you to apply your new knowledge in the context of a realistic scenario. Whether you’re a hobbyist eager to get cracking on your next project, or a professional developer looking to unlock your next promotion, pick up a copy and make a start! Whatever your motivation, by the end of this book, you’ll have the confidence and understanding to make it happen with TypeScript.
Table of Contents (16 chapters)
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Preface

Enhancing Promises with Types

The example we're working with so far specifies the type of input to the promise, but we have to provide a type for the result in each step of the chain. That's because TypeScript doesn't know what the promise may resolve to so we have to tell it what kind of type we're getting as the result.

In other words, we're missing out on one of TypeScript's most powerful features: type inference. Type inference is the ability for TypeScript to know what the type of something should be without having to be told. A very simple example of type inference would be the following:

const hello = "hello";

No type is specified. This is because TypeScript understands that the variable hello is being assigned a string and cannot be reassigned. If we try to pass this variable as an argument to a function that expects another type, we will get a compilation error, even though we never specified the type. Let's apply type...

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