What are promises in Express.js?

What are promises in Express.js?

Promises in Express.js are used to handle asynchronous operations, allowing you to write cleaner and more manageable code.

Can you give me an example of how to use promises in an Express route?

Sure! Here's a simple example:

app.get('/data', (req, res) => {
    getDataFromDatabase()
        .then(data => res.json(data))
        .catch(err => res.status(500).send(err.message));
});

What happens if a promise is rejected?

If a promise is rejected, the error can be caught using the .catch() method, allowing you to handle the error gracefully.

Are there any alternatives to using promises?

Yes, you can use callbacks or async/await syntax, which is built on top of promises for a more synchronous style.