Async/Await

Short explanation

async/await lets you write asynchronous code in a synchronous-like style by awaiting Promises. It's syntactic sugar over Promises but improves readability and error handling.

Syntax example

async function fetchData() {
  try {
    const res = await fetch('/api/data');
    const data = await res.json();
    return data;
  } catch (err) {
    console.error(err);
  }
}

How JS handles it internally

An async function returns a Promise. The runtime pauses the function at each await until the awaited Promise resolves, then resumes execution. The event loop and microtask queue are involved in resolving awaited Promises.

FAQ

Q: Are async functions slower than Promises?

A: Slight overhead exists, but the clarity and maintainability usually outweigh performance costs in application code.