TypeScript

What is TypeScript?

At its core, TypeScript is a superset of JavaScript—which means it builds on top of JavaScript by adding static typing.

Think of it as

TypeScript = JavaScript + Types

You write valid JavaScript, but with the power of types, interfaces, type inference, and other features that help catch bugs earlier, improve editor tooling (like auto-completion and refactoring), and make your codebase more robust as it grows.

TypeScript compiles to JavaScript, which means your browser or Node.js doesn’t need to support TypeScript directly. You write .ts or .tsx files, then transpile them into plain JavaScript (usually sits under the /dist folder).

What This Guide Covers

This guide is for those who've finished the JavaScript section and want to learn just the most essential TypeScript features to be productive in React.

We’re not going to cover everything about TypeScript (like advanced conditional types). Instead, we focus on:

• What you actually use daily in React codebases

• Concepts that improve code clarity, type safety, and developer productivity

By the end of this guide, you'll understand how to:

• How to define and extend types and interfaces for your components and logic

• When and how to use handy utility types like Pick, Omit, and Partial

• How to safely type component props, events, refs, and hooks

• How to avoid common mistakes (like reaching for any too quickly)

• And ultimately, how to make your code more predictable, scalable, and enjoyable to work with