Redux-Basics.js

const redux = require('redux');
const createStore = redux.createStore;

const initialState = {
    counter:0
}

// Order matters  Reducer -> Store -> Subscription -> dispatcher

// Reducer
const reducer = (state = initialState,action) => {
    if(action.type === 'INC_COUNTER'){
        return {
            ...state,
            counter: state.counter+1
        }
    }else if(action.type === 'ADD_COUNTER'){
        return {
            ...state,
            counter: state.counter+action.value
        }
    }
    return state;
}

//Store
const store = new createStore(reducer);
console.log(store.getState());

//Subscription
store.subscribe(() => {
    console.log('[Subscribed Data] ',store.getState());
});

// Disptacher
store.dispatch({type: 'INC_COUNTER'});
store.dispatch({type: 'ADD_COUNTER',value:10});
console.log(store.getState());