Follow this guide to see how Expo simplifies mobile app development in React Native with Expo SDK and developer tools.

Expo is an open-source platform that makes developing cross-platform iOS and Android mobile apps much easier than before. The Expo SDK is a series of native libraries for each iOS and Android platform, and it allows JavaScript to access the system features of the device such as the camera, push notifications, local storage, contacts, and other hardware and operating system APIs.

Prerequisites

To install Expo, you need Node.js version 12 or newer in your machine because Expo’s command-line tools and dependency management relies on the Node platform. You can check your Node version by running the Node -v command on your terminal.

Expo offers a command-line interface called Expo CLI. It is used to test the app while it’s being developed either in iOS or Android.

npm install -g expo-cli

Installing Expo mobile client for iOS and Android

To test the functionality of your mobile app, you’ll need the Expo client app for Android and iPhone. You can find them in Google Play Store and the App Store.

Building an Expo app

Let’s build an Expo app and see how it works. You can create a new Expo app with the following command:

expo init your_app_name

Replace your_app_name with the name of the app you wish to build. Once you hit enter, you’ll be prompted to select the type of template for your app.

You can choose any template that works for your app. For now, I’ll pick “blank workflow” to make things simple.

Next, you’ll be prompted to install the template via Yarn. If you have already installed Yarn, choose yes, or otherwise, choose continue. Once you follow the next steps, your app will be ready to use.

Jump into the following commands to start the project.

cd <app_name>
npm start or yarn start

After successfully executing the above commands, it will launch a new development metro environment. You will get the QR code, which should be scanned via Expo’s client app in Android and the default Camera app in iPhones. By now, you are all set to go.

#react-native #react #javacript #expo