使用异步函数将属性添加到对象数组

Question

我想将tripPrice 添加到我数组的每个对象中，但最后，tripPrice 是undefined

这是我的代码：

async getTest(req, res) {

       let result = await this.model.Pricing.getTest(req.params);  
       result.map(async item => {
            let params = {
                originStation: item.fromStation,
                destStation: item.toStation,
                cityCode: 1,
                carClass: item.carType,
              }
            let tripPrice = await axios.post(`${appConfig.gpsServer.host}/api/trip/price`, params);
            item.price = tripPrice
            return item
        })
   return result
}

如何在调用 API 后向我的对象添加新属性？它无需异步等待和 API 调用即可工作

Answer 1

使用Async/Await 和Promise.all

const getTest = async (req, res) => {

try {
    let result = await this.model.Pricing.getTest(req.params);
    const promises = [];

    result.map(item => {
        const params = {
            originStation: item.fromStation,
            destStation: item.toStation,
            cityCode: 1,
            carClass: item.carType,
        }
        const promise = new Promise((resolve, reject) => {
            axios.post(`${appConfig.gpsServer.host}/api/trip/price`, params).then(tripPrice => {
                item.price = tripPrice || null;
                resolve(item)
            }).catch(e => {
                reject(e)
            })
        })
        promises.push(promise);
    })


    const result = await Promise.all(promises).then(r => r).catch(error => { throw error })
    console.log(result)
    return result;
} catch (error) {
    console.log(error)
}

}

Answer 2

试试这个

async getTest(req, res) {

       let result = await this.model.Pricing.getTest(req.params);  
       resultWithTripePrice = result.map(async item => {
            let params = {
                originStation: item.fromStation,
                destStation: item.toStation,
                cityCode: 1,
                carClass: item.carType,
              }
            let tripPrice = await axios.post(`${appConfig.gpsServer.host}/api/trip/price`, params);
            item.price = tripPrice
            return item
        })
        return resultWithTripePrice
}

Map 函数用于从值列表生成修改版本，它与 for 循环不同。 Map 函数将返回更新后的列表，您可以使用该变量，在https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map 上阅读更多内容