#16 What are async and await in JavaScript?

async and await are keywords in JavaScript used to handle asynchronous operations in a cleaner, more readable way than traditional promises or callbacks.

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🔹 async Function:

• Declares a function as asynchronous.
• Always returns a Promise.
• Allows the use of await inside it.

async function getData() {
  return "Hello";
}

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🔹 await Keyword:

• Can only be used inside an async function.
• Pauses the execution of the function until the Promise is resolved.
• Makes asynchronous code look like synchronous code.

async function fetchData() {
  const response = await fetch("https://api.example.com/data");
  const data = await response.json();
  console.log(data);
}

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✅ Comparison with Promises:

Using .then():

fetch(url)
  .then(res => res.json())
  .then(data => console.log(data));

Using async/await:

async function getData() {
  const res = await fetch(url);
  const data = await res.json();
  console.log(data);
}

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✅ Error Handling:

Use try...catch with async/await for cleaner error handling.

async function getUser() {
  try {
    const res = await fetch("invalid-url");
    const data = await res.json();
    console.log(data);
  } catch (error) {
    console.error("Error:", error);
  }
}

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📝 In Summary:

• async declares a function that returns a Promise.
• await waits for a Promise to resolve before continuing.
• Together, they make asynchronous code easier to write and read, avoiding nested .then() chains.