Redux stores initialization, dispatchers and reducer in a nutshell

redux-in-nutshell.js

const userReducer = (state={}, action) => {
  switch(action.type) {
    case 'CHANGE_NAME': {
      // Immutable way
      state = {...state, name: action.payload}
      break;
    }
    case "CHANGE_AGE": {
      state = {...state, age: action.payload}
      break;
    }
  }
  return state;
};

const defaults = {}
const tweetsReducer = (state=[], action) => {
  return state;
};

// Limit changing of user to userReducer
const reducers = combineReducers({
  user: userReducer,
  tweets: tweetsReducer
})

const store = createStore(reducers);
store.subscribe(() => {
  console.log('Store changed', store.getState())
})

// type is mandatory, payload's name can be changed
// one action can trigger multiple side effects, that are completely de-coupled from each another
store.dispatch({ type: 'CHANGE_NAME', payload: 'Will' });
store.dispatch({ type: 'CHANGE_AGE', payload: 29 });
store.dispatch({ type: 'CHANGE_AGE', payload: 23 });