Warning: isMounted(…) is deprecated in plain Javascript Classes

Question

I am implementing 2 screens using react-navigation. But I got the warning below while navigating to the second page:

Warning: isMounted(...) is deprec

Answer 1

Is is actually a React-Native issue

You can wait and check when a fix is available here: https://github.com/facebook/react-native/issues/18868

Or in the meantime you can hide the warning like suggested.

Answer 2

The following solution works for me:

import { YellowBox } from 'react-native';
YellowBox.ignoreWarnings(['Warning: isMounted(...) is deprecated', 'Module RCTImageLoader']);

Answer 3

This is not from react-navigation as i looked into the node_modules and react-navigation doesn't use isMounted, Its coming from somewhere within React-Native, I have also done same hack used by @Romsun

    import { YellowBox } from 'react-native';
YellowBox.ignoreWarnings(['Warning: isMounted(...) is deprecated', 'Module RCTImageLoader']);

Answer 4

react-navigation issue is now closed, you can look here

They are stating that it is a problem somewhere inside of react-native

Answer 5

If you are using an expo client, update your version to expo@27.0.2 which fixes this warning. . .