React Introduction

Introduction

React is used to build software that talks close to the machine — operating systems, embedded firmware, databases, and more.

In this course you will learn React step by step. This page introduces the language and what you need to get moving.

Syntax

A minimal React program looks like this:

Basic Example

Output

When you run the program above, you will see:

Code Explanation

1. Write markup or script
2. Run in browser or interpreter
3. Check output

Real-World Usage

React shows up in production systems worldwide — not just textbooks.

• Desktop and server software
• Games and graphics
• Devices and IoT
• Tools other developers rely on

Common Mistakes

Skipping setup. Install a compiler or runtime before chasing advanced topics.

Not running code. Reading alone will not build muscle memory.

Best Practices

• Type every example yourself instead of only reading
• Change values in the sample code and see what breaks
• Fix errors yourself before peeking at solutions

Tips

Tip: Keep a notes file with syntax snippets you use often for Introduction.

Summary

1. You studied Introduction in React.
2. Practice with the exercises at the bottom of this page.
3. Move to the next lesson when you can write the examples from memory.