问题描述
我正在努力使用.map并等待。如何获取下面的内容，等待地图完成？
export async function buildDeviceArray(userIdList){ //userIdList is an array of ids
await userIdList.map(myFunction2)
return deviceArray1 // returns straight away,rather than waiting for the .map to complete
async function myFunction2(item) {
let user = await wixData.get("OurUsers",item)
let device = await wixData.get("Devices",user.deviceDefault)
let output = { "label": device.deviceReference,"value": user.deviceDefault }
if (user.deviceDefault) deviceArray1.push(output)
console.log(deviceArray1);
return
}
解决方法
这是如何将var originalArray = [1,2,3,4];
async function multiplyBy2(x) {
await new Promise(r => setTimeout(r,5000)); // half second
return 2*x;
}
async function run() {
var promiseArray = originalArray.map(multiplyBy2)
var answerArray = await Promise.all(promiseArray);
console.log(answerArray);
}
run();与异步回调函数一起使用的示例。
get all listed products