Async/Await - Modern Promise Syntax

Async/Await - Modern Promise Syntax

Async/await is syntactic sugar for promises, making asynchronous code look and behave more like synchronous code. It's easier to read and write.

Async Functions

// Function marked with 'async' always returns a Promise
async function fetchData() {
  return 'Data';
}

// Arrow function
const fetchData = async () => {
  return 'Data';
};

Await Keyword

async function getData() {
  // await pauses execution until promise resolves
  const data = await fetch('/api/data');
  const json = await data.json();
  return json;
}

Error Handling

// Using try-catch with async/await
async function fetchData() {
  try {
    const response = await fetch('/api/data');
    const data = await response.json();
    return data;
  } catch (error) {
    console.error('Error:', error);
    throw error;
  }
}

Multiple Async Operations

// Sequential (one after another)
async function sequential() {
  const first = await fetch('/api/first');
  const second = await fetch('/api/second');
  return { first, second };
}

// Parallel (at the same time)
async function parallel() {
  const [first, second] = await Promise.all([
    fetch('/api/first'),
    fetch('/api/second')
  ]);
  return { first, second };
}

Benefits of Async/Await

• Cleaner, more readable code
• Easier error handling with try-catch
• Better debugging experience
• Works with existing promise-based APIs