Expo

Description #

Expo is an open-source platform for building universal native apps with JavaScript and React Native, offering powerful tools and services out of the box.

History #

Expo was created in 2016 by Charlie Cheever and the Expo team to simplify the React Native development experience by bundling tools, services, and libraries into a developer-friendly CLI and cloud ecosystem.

Hello World Code #

import { Text, View } from 'react-native';

export default function App() {
  return (
    <View>
      <Text>Hello, World!</Text>
    </View>
  );
}

How to Run #

Option 1: Online
Snack.expo.dev

Option 2: Local

npm install -g expo-cli
expo init HelloWorld
cd HelloWorld
expo start

Key Concepts #

• Uses React Native core
• No native build tooling required
• Over-the-air updates
• Device APIs via Expo SDK
• Cloud build service
• Developer-friendly CLI and GUI
• Push notifications and auth modules
• Web + iOS + Android from one codebase
• Instant previews with QR code
• Ejectable for native customization

Try It Online #

https://snack.expo.dev

Fun Facts #

Expo allows real-time app testing on physical devices without ever touching Xcode or Android Studio.

Resources #

Official site
Docs
GitHub
Community