CODE EXAMPLE FOR JAVASCRIPT

exit react native app

componentWillMount() {
   BackHandler.addEventListener('hardwareBackPress', this.backPressed);
}

componentWillUnmount() {
   BackHandler.removeEventListener('hardwareBackPress', this.backPressed);
}

backPressed = () => {
  Alert.alert(
    'Exit App',
    'Do you want to exit?',
    [
      {text: 'No', onPress: () => console.log('Cancel Pressed'), style: 'cancel'},
      {text: 'Yes', onPress: () => BackHandler.exitApp()},
    ],
    { cancelable: false });
    return true;
}