Asynchronous programming in JavaScript can be tricky, but mastering async/await can dramatically clean up your code. Not only that, but it can also improve performance and make your code easier to read and maintain.
If in doubt always refer to the docs, which are excellent.
Here’s the crux of async/await in as efficient an article as I can make it.
Understanding Async/Await
async
functions return aPromise
.await
pauses the execution until thePromise
resolves.await
only works inside async functions.- This pattern simplifies asynchronous code, making it look synchronous.
Error Handling
- Use
try...catch
blocks within async functions. - This approach helps in handling errors gracefully and keeps code clean.
Avoiding Common Pitfalls
- Be cautious with await in loops; it can lead to performance issues. A good linter or compiler should flag this.
- Prefer
Promise.all
for concurrent tasks to optimize execution time. - Use
Promise.allSettled
to handle errors gracefully. This method returns an array of results, including errors.
Refactoring Callbacks
- Transform traditional callback-based functions into async functions.
- This shift enhances readability and maintainability.
- Before we had
async/await
, we had callbacks. Callbacks are functions that are passed as arguments to other functions. They are executed when the parent function completes. Avoid callback hell by using async/await.