async/await basics

await is chain syntax

Two keywords rewrite promise chains as ordinary-looking lines:

• async before a function makes it always return a promise. return 5 inside it fulfills that promise with 5.
• await promise (only inside async functions) pauses the function until the promise settles, then hands you the unwrapped value.

Crucial nuance: await pauses that one function, not the program. The rest of your script keeps running, and the paused function resumes later as a microtask (lesson 4-2).

Why the syntax exists: .then chains still read inside-out once conditions, loops, or retries get involved — try writing "attempt three times, then fall back" as a chain. With await, async code uses the same if/for/try tools as everything else, which is why it is the default style in modern codebases and the one interviewers expect.

Errors: plain try/catch

With await, a rejected promise throws at the await line. So error handling is the try/catch you already know, instead of .catch chains from lesson 5-3:

async function load() {
  try {
    const user = await fetchUser(42);
    console.log(user);
  } catch (err) {
    console.log("fallback: guest");
  }
}

Same rejection, same recovery, straighter code. This is the style most codebases and interviewers expect from you by default.