cedrickchee / typescript-deep-dive

Hands-on TypeScript programming exercises based on "The definitive guide to TypeScript" book.

My TypeScript Hands-on

This repo contains notes and exercises from my deep dive into TypeScript and I learn by doing the lessons from the The definitive guide to TypeScript book.

A little context

I am a polyglot programmer. Over the 10+ years, I have written codes both professionally and as a hobby in many programming languages—from Ruby to JavaScript, Go, Java, and Python. My motivation of learning TypeScript is to improved code quality as I have been writing a lot of JavaScript code since 2013 in my role as a front-end developer, hybrid mobile app developer, and React Native mobile app developer.

What is TypeScript

TypeScript is JavaScript that scales.

TypeScript is a typed superset of JavaScript that compiles to plain JavaScript. Any browser. Any host. Any OS. Open source.

Motivation and Design Goals of TypeScript

Why TypeScript

There are two main goals of TypeScript:

• Provide an optional type system for JavaScript.
• Provide planned features from future JavaScript editions to current JavaScript engines.

The desire for these goals is motivated below.

Why add types to JavaScript?

Types have proven ability to enhance code quality and understandability. Specifically:

• Types increase your agility when doing refactoring. It's better for the compiler to catch errors than to have things fail at runtime.
• Types are one of the best forms of documentation you can have. The function signature is a theorem and the function body is the proof.

However types have a way of being unnecessarily ceremonious. TypeScript is very particular about keeping the barrier to entry as low as possible. Here's how:

• Your JavaScript is TypeScript
• Types can be implicit
• Types can be explicit
• Types are structural
• Type errors do not prevent JavaScript emit
• Types can be ambient
• Future JavaScript => Now

Project Structure

WIP. Please check again soon.

Thank you for your interest.