How do promises compare to callbacks in Node.js?

How do promises compare to callbacks in Node.js?

Promises provide a cleaner and more manageable way to handle asynchronous operations compared to callbacks. With callbacks, you can end up with 'callback hell' if you have multiple nested callbacks, making the code hard to read and maintain. Promises allow you to chain operations and handle errors more gracefully.

Can you give me an example of both?

Sure! Here's a simple example:

Using a callback:

function fetchData(callback) {
    setTimeout(() => {
        callback('Data received');
    }, 1000);
}

fetchData((data) => {
    console.log(data);
});

Using a promise:

function fetchData() {
    return new Promise((resolve) => {
        setTimeout(() => {
            resolve('Data received');
        }, 1000);
    });
}

fetchData().then((data) => {
    console.log(data);
});

What are the advantages of using promises?

Some advantages of using promises include:

1. Better error handling with .catch().
2. Chaining multiple asynchronous operations.
3. Avoiding callback hell, leading to cleaner code.

Are there any downsides to using promises?

Yes, while promises are more manageable, they can still lead to unhandled promise rejections if not properly handled. Additionally, they can introduce complexity if not used correctly, especially when mixing with callbacks.