Async / Await

Async/await is syntactic sugar over Promises, making async code look and behave like synchronous code.

Basic Syntax

async function fetchUser(id) {
  const response = await fetch(\`/api/users/\${id}\`)
  const user = await response.json()
  return user
}

// Arrow function version
const fetchUser = async (id) => {
  const response = await fetch(\`/api/users/\${id}\`)
  return response.json()
}

Error Handling with try/catch

async function loadData() {
  try {
    const response = await fetch('/api/data')

    if (!response.ok) {
      throw new Error(\`HTTP error: \${response.status}\`)
    }

    const data = await response.json()
    return data

  } catch (error) {
    console.error('Failed to load:', error.message)
    return null
  } finally {
    console.log('Request complete')
  }
}

// Call it
const data = await loadData()

Parallel Requests

// Sequential (slow — waits for each)
const user = await fetchUser(1)
const posts = await fetchPosts(1)

// Parallel (fast — runs simultaneously)
const [user, posts] = await Promise.all([
  fetchUser(1),
  fetchPosts(1)
])