在redux reducer和action中编写相同的函数行为

// action types
const INCREMENT = 'INCREMENT';
const DECREMENT = 'DECREMENT';

// actions
const increment = () => {
  return {
    type: INCREMENT
  };
};

const decrement = () => {
  return {
    type: DECREMENT
  };
};

// reducer
const initialState = {
  count: 0
};

const counterReducer = (state = initialState, action) => {
  switch (action.type) {
    case INCREMENT:
      return {
        ...state,
        count: state.count + 1
      };
    case DECREMENT:
      return {
        ...state,
        count: state.count - 1
      };
    default:
      return state;
  }
};

// 使用Redux的store和相关中间件
// ...

// 调用action来更新状态
store.dispatch(increment());
store.dispatch(decrement());