CODEWITHSUNDEEP
react-native
Ryan McDermott
Ryan McDermott

Reputation: 6305

React Native DEV and PROD variables

How do I know if my React Native app is running in production or development? Is there some sort of way within JavaScript to tell? Is there a global that is passed in?

Upvotes: 108

Views: 69348

Answers (3)

Austin
Austin

Reputation: 6719

You can use the __DEV__ global variable in JavaScript to determine if you're using React Native packager or not. If you are running your app in the iOS Simulator or Android emulator __DEV__ will be set to true.

https://reactnative.dev/docs/javascript-environment

Upvotes: 159

Raphael Pinel
Raphael Pinel

Reputation: 2800

You can use the __DEV__ variable. By default if you run your app with npx react-native run-ios or npx react-native run-android, it will run in Debug mode and __DEV__ will be true. In release mode, __DEV__ will be false. You can use it this way:

const CLOUD_API_BASE_URL = __DEV__ ? 'https://api-dev.yourdomain.com' : 'https://api-prod.yourdomain.com';

You can run the app in Release mode with the terminal: react-native run-android --variant release #android react-native run-ios --configuration Release #ios

Or open the ios folder in XCode, choose Product > Scheme > Edit Schemes xcode edit scheme Select Run in the left menu. For Build Configuration, choose 'Release' and uncheck 'Debug executable'

enter image description here

In Android Studio, similarly, you can set the build variant to release enter image description here

Upvotes: 10

Abhishek Kumar
Abhishek Kumar

Reputation: 1015

When the __DEV__ variable is set to true, it turns on a bunch of useful development warnings. For production, it is recommended to set __DEV__=false.

Upvotes: 3

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