Async and Await

Async and Await

async and await make promises much easier to write and read.

The async keyword

async marks a function as asynchronous. It always returns a promise:

async function getData() {
  return "data";
}
getData(); // a Promise

The await keyword

await pauses an async function until a promise settles, then gives you the result:

async function showUser() {
  const user = await fetchUser();
  console.log(user);
}

Await only works inside async

You can only use await inside an async function.

Error handling with try/catch

async function getData() {
  try {
    const data = await fetchSomething();
    console.log(data);
  } catch (err) {
    console.log("Failed: " + err.message);
  }
}

Why async/await?

• Reads like normal synchronous code.
• No more chaining .then and .catch everywhere.
• Errors handled with familiar try/catch.

TL;DR

• async functions return promises.
• await pauses until a promise settles.
• await only works inside async functions.
• Use try/catch for errors.