How to Handle Async Operations with Promises

Recognize operations that take time, such as network requests or reading files. Instead of passing a callback function into these operations, design them to return a Promise object.

Call the async function. Attach a .then() method to the returned Promise. Provide a callback function inside .then(). The engine guarantees this callback will execute strictly once the data is ready.

If you need to make sequential API calls, return the second Promise from inside the first .then(). This allows you to attach another .then() at the root level, flattening the code and avoiding nested 'Callback Hell'.

Attach a single .catch() block at the very end of your Promise chain. If any of the chained Promises fail or reject, execution will immediately jump down to this catch block, making error handling incredibly clean.

For even cleaner code, prefix your function with the 'async' keyword. You can now use the 'await' keyword directly in front of the Promise. The engine will pause the function execution until the Promise resolves, making asynchronous code look perfectly synchronous.

When using Async/Await, you handle errors using standard JavaScript try/catch blocks. Wrap your awaited Promises in a try block, and handle rejections cleanly in the catch block.