Rediscovering JavaScript

Async and Await

We saw how promises are superior to callbacks, but there’s one drawback to using promises. The structure of synchronous imperative code is drastically different from the structure of asynchronous code that uses promises. Unlike the sequential code that flows naturally from one statement or expression to the next, we have to get our head wrapped around the then() and the catch() sequence.

The async and await feature was introduced to keep the code structure identical between synchronous and asynchronous code. This does not affect the way we write asynchronous functions, but it largely changes the way we use them.

There are two rules to using this feature:

• To be able to use an asynchronous function as if it were a synchronous ...