Redux Hello World implemented in React Native. Tutorial Link: https://medium.com/@ibjects/tutorial-redux-react-redux-and-redux-persist-from-scratch-28249ee914e7

App.js

import React from 'react';

import { NavigationContainer } from '@react-navigation/native';
import { createStackNavigator } from '@react-navigation/stack';

import Home from './src/screens/Home';
import ReduxExample from './src/screens/ReduxExample';

import { createStore } from 'redux';
import { Provider } from 'react-redux';
import { rootReducer } from './src/utils/redux/reducers';

const Stack = createStackNavigator();

function App(props) {
    return (
    <Provider store={store}>
      <NavigationContainer theme={SukhanTheme}>
        <Stack.Navigator>
          <Stack.Screen name="Home" component={Home} />
          <Stack.Screen name="ReduxExample" component={ReduxExample} />
        </Stack.Navigator>
      </NavigationContainer>
    </Provider>
  );
}

export const store = createStore(rootReducer);
export default App;

reducers.js

const InitialState = { count: 0 }

function rootReducer(state = InitialState, action) {

    switch (action?.type) {
        case 'counter/increment': return { ...state, count: state.count + 1 };
        case 'counter/decrement': return { ...state, count: state.count - 1 };
        default: return state;
    }
};

export { rootReducer };

ReduxExample.js

import React from 'react';
// import { store } from '../../App';
import { View, Text, Button } from 'react-native';

import { useSelector, useDispatch } from 'react-redux'
import { rootReducer } from '../utils/redux/reducers';

function ReduxExample(props) {

    const counter = useSelector(rootReducer);
    const dispatch = useDispatch();

    return (
        <View>
            <Text>Redux Hello World</Text>
            <Text>Counter {counter.count}</Text>
            <View style={{ flexDirection: 'row', justifyContent: 'space-between', margin: 24 }} >
                <Button title='Increment' onPress={() => { dispatch({ type: 'counter/increment' }) }} />
                <Button title='Decrement' onPress={() => { dispatch({ type: 'counter/decrement' }) }} />
            </View>
        </View>
    );
}

export default ReduxExample;