how to run react native app

JavaScript
npm install -g react-native-cli

//cd to the file where your react native projects will be 
react-native init albums

// Run instructions for  IOS/Android
cd projects/albums 

npx react-native run-ios
npx react-native run-android
npm install -g react-native-clinpx react-native init AwesomeProject
react-native run-android 
react-native run-ios$ npx react-native init firstapp
react-native start
Source

Also in JavaScript: