How can I create custom middleware in Express.js?

How can I create custom middleware in Express.js?

To create custom middleware in Express.js, you define a function that takes three parameters: req, res, and next.

Can you give me an example of a simple logging middleware?

Sure! Here's a simple logging middleware:

function logger(req, res, next) {
    console.log(`${req.method} ${req.url}`);
    next();
}

How do I use this middleware in my Express app?

You can use it by calling app.use(logger); in your Express app setup.

What if I want to add more functionality to my middleware?

You can add more logic inside the middleware function, like checking user authentication or modifying the request object.