'use strict';  // 為了更好地識別es6語法

// 拆分reducer
const Redux = require('redux');
const createStore = Redux.createStore;
const combineReducers = Redux.combineReducers;

// state => {a: [], b: []}
// action => {type: string, data: string}
// const reducers => {a: fucntion(state, action) {}, b: function(state, action) {}}
 


// 這裡的state是部分的state，是{a: []}
function aReducer(state, action) {
    if (typeof state === 'undefined') 
        return [];
    switch(action.type) {
        case 'a':
            return state.concat([action.data]);
        default:
            return state;
    }
}

function bReducer(state, action) {
 

    if (typeof state === 'undefined') 
        return [];
    switch(action.type) {
        case 'b':
            return state.concat([action.data]);
        default:
            return state;
    }
}

const reducer = combineReducers({a: aReducer, b: bReducer});
const store = createStore(reducer, {a: [1111
 
], b: [2222]});

store.subscribe(function listener() {
    console.log(store.getState());
})

let actionA = {
    type: 'a',
    data: 'zcw'
}

let actionB = {
    type: 'b',
    data: 'hy'
}

store.dispatch(actionA);
store.dispatch(actionB);