reactjs - react.js 中选择器的问题。如果我在 react.js 中使用选择器并且如果我在其中一个组件中导出它会在该选择器部分显示错误

Question

export const initialState = {
  basket: [],
};

// reducer takes care about adding and removing items from the basket

// selector
export const getBasketTotal = (basket) =>
  basket?.reduce((amount, item) => item.price + amount, 0);

// the above code helps us tally the total amount of products

const reducer = (state, action) => {
  switch (action.type) {
    case "ADD TO BASKET":
      return {
        ...state,
        basket: [...state.basket, action.items],
      };
    // the above code helps us to push items to the basket with current elemnts in the basket
    default:
      return state;
  }
};
export default reducer;

它显示的错误在 export const getBasketTotal 中，它显示的错误是匿名函数

Answer 1

选择器通常接收整个状态对象。我怀疑你想访问一个state.basket.

export const getBasketTotal = (state) =>
  state.basket?.reduce((amount, item) => item.price + amount, 0);

对我来说，其他看起来有点可疑的是"ADD TO BASKET"动作：

basket: [...state.basket, action.items],

action.itemsIMO 意味着多个项目，所以我认为您可能希望将项目分散到basket数组中。

basket: [...state.basket, ...action.items],