How to do logging in React Native?

Question

How can I log a variable in React Native, like using console.log when developing for web?

Answer 1

There are 3 methods that I use to debug when developing React Native apps:

1. console.log(): shows in console
2. console.warn(): shows in yellow box bottom of application
3. alert(): shows as a prompt just like it does in web

Answer 2

Chrome Devtool is the best and easiest way for logging and debugging.

Answer 3

Press [command + control + Z] in Xcode Simulator, choose Debug JS Remotely, then press [command + option + J] to open Chrome developer tools.

Xcode Simulator Img

refer：Debugging React Native Apps

Answer 4

You use the same thing that is used for regular web. The console command also works in this case. For example, you can use console.log(), console.warn(), console.clear() etc.

You can use Chrome Developer to use the console command when you're logging while you are running your React Native app.

Answer 5

console.log works.

By default on iOS, it logs to the debug pane inside Xcode.

From the IOS simulator press (⌘+D) and press Remote JS Debugging. This will open a resource, http://localhost:8081/debugger-ui on localhost. From there use Chrome Developer tools javascript console to view console.log

Answer 6

Use console.debug("text");

You will see the logs inside the terminal.

Steps:

• Run the application:

react-native run-ios        # For iOS
react-native run-android    # For Android

• Run the logger:

react-native log-ios        # For iOS
react-native log-android    # For Android