JavaScript Async / Await

async and await are modern JavaScript features that make working with Promises easier and code more readable, avoiding the “callback hell.”

1️⃣ Async Functions

• An async function always returns a Promise.

• If a function returns a value, it is wrapped in a resolved Promise.

• You can use await only inside async functions.

2️⃣ Await Keyword

• await pauses the execution of the async function until the Promise resolves.

• It can only be used inside async functions.

3️⃣ Error Handling with Try / Catch

4️⃣ Sequential vs Parallel Execution

Sequential Execution (Slower)

Parallel Execution (Faster)

5️⃣ Real World Example: Fetch API

6️⃣ Key Rules

1. Always use await inside async functions.

2. async functions return a Promise.

3. Use try/catch to handle errors.

4. Combine with Promise.all() for parallel execution.

⭐ Summary Table