What are the differences between callbacks and promises in Node.js?

What are the differences between callbacks and promises in Node.js?

Callbacks are functions passed as arguments to other functions, executed after a task is completed. Promises, on the other hand, represent a value that may be available now, or in the future, or never. They provide a cleaner way to handle asynchronous operations.

Can you give me an example of a callback in Node.js?

Sure! Here's a simple example:

const fs = require('fs');
fs.readFile('file.txt', 'utf8', (err, data) => {
    if (err) {
        console.error(err);
        return;
    }
    console.log(data);
});

In this example, readFile takes a callback that gets executed once the file reading is complete.

How about an example using promises?

Absolutely! Here's how you can use promises:

const fs = require('fs').promises;
fs.readFile('file.txt', 'utf8')
    .then(data => console.log(data))
    .catch(err => console.error(err));

In this case, readFile returns a promise that resolves with the file data or rejects with an error.

Which one is better to use?

Promises are generally preferred over callbacks because they help avoid callback hell, making the code cleaner and easier to read. They also provide better error handling.