Project: orders in sequence

JavaScript · Unit 18: Asynchronous code

The practice comes with a parcel tracker: api + "/paquete/" + code answers with the code, its state and the days left, which it calls dias.

The codes that exist are 7 and 9. With any other one the answer still arrives, but with ok as false and no parcel data in it.

const api = "https://api.bybecode.dev";
const u = api + "/paquete/7";
const r = await fetch(u);
const d = await r.json();
console.log(d.dias);

Prints

Exercises in this lesson

You do them in the app, which checks them on the spot and explains why.

1. Complete the code
Fill in exists(code), which answers whether that address has a parcel.
2. Write the code
Write daysLeft(code): the days the parcel still has left, or -1 if that address has no parcel at all.
3. Write the code
Write allDays(codes): an array with the days left for every code, in the same order. The requests don't depend on each other, so they go together with Promise.all. The daysLeft function is already written above.

It opens in your browser. This lesson is part of the full plan; the first unit of each course is free.