Welcome to React

React is a JavaScript library for building user interfaces. Created by Facebook, it has become the most popular frontend framework, used by companies like Netflix, Airbnb, and Instagram.

Why React?

React makes it easy to create interactive UIs by breaking your interface into reusable components. Each component manages its own state and can be composed together to build complex applications.

How This Course Works

In this course, you'll learn React concepts through hands-on exercises. Since React requires a build process to compile JSX, our exercises focus on understanding the patterns and concepts that you'll apply when building real React applications.

The Component Mindset

Think of your UI as a tree of components. Each component is responsible for one piece of the interface.

Exercise: Your First Component Function

Create a function that returns a welcome message:

Exercise: Dynamic Greeting

Create a greeting function that uses a variable:

Key Takeaways

1. React components are functions - They take input and return UI descriptions
2. Think in components - Break your UI into small, reusable pieces
3. Composition is key - Build complex UIs by combining simple components
4. JavaScript knowledge transfers - Your JS skills apply directly to React

In the next lesson, we'll learn about JSX - React's special syntax for describing UI.