小编tel*_*lls的帖子

我正在使用github上的'simplest-redux-example',我添加了第二个减少state.count的reducer.如果我在switch case语句中有递增和递减reducers,它可以正常工作.我想要进行的练习是将减速器分成尽可能多的模块化部件.此代码抛出一个错误,指出count未定义.

import React from 'react';
import { createStore, combineReducers } from 'redux';
import { Provider, connect } from 'react-redux';

// React component
class Counter extends React.Component {
  render(){
    const { value, onIncreaseClick, onDecreaseClick } = this.props;
    return (
      <div>
        <span>{value}</span>
        <button onClick={onIncreaseClick}>Increase</button>
        <button onClick={onDecreaseClick}>Decrease</button>
      </div>
    );
  }
}

// Action:
const increaseAction = {type: 'increase'};
const decreaseAction = {type: 'decrease'};

// Reducer:
function counter(state, action) {
  let count = state.count;
  switch(action.type){
    case 'increase':
      return {count: …