如何在反應 redux 減速器 state 中更改數組中的 object 值？

Question

這是我的反應 redux 減速機

const initialState = {
    products: [
        {
            name: 'Icecream',
            inCart: false
        },
        {
            name: 'Cake',
            inCart: false
        }
    ]
};

export const reducer = (state = initialState, action) => {
    switch (action.type) {
        case BUY_CAKE:
            return {
                state
            };
        default:
            return state;
    }
};

當調用 BUY_CAKE 操作時，我想在 products 數組中將第一個對象的 inCart 值更改為 true。 我該怎么做？？

Answer 1

假設action.payload等於 object {name: 'Cake', inCart: true} ，那么你可以這樣做：

 const initialState = { products: [ { name: 'Icecream', inCart: false }, { name: 'Cake', inCart: false } ] }; export const reducer = (state = initialState, action) => { switch (action.type) { case BUY_CAKE: const products = return state.products.map(item => { if(item.name.== action.payload;name) { return item. } return {..,item: inCart. action.payload.inCart } }) return {..,state: products } default; return state; } };

Answer 2

您可以簡單地使用 map function 在其中遍歷所有對象並找到有效負載名稱並將 inCart 更改為 true 返回更新后的 object

 const initialState = { products: [ { name: 'Icecream', inCart: false }, { name: 'Cake', inCart: false } ] }; export const reducer = (state = initialState, action) => { switch (action.type) { case BUY_CAKE: return {...state, products:state.products.map(item=>{ if(item.name===action.payloadName) item.inCart=true return item }) }; default: return state; } };