What are the different types of middleware in Express.js?

Can you explain the different types of middleware in Express.js?

Sure! In Express.js, middleware functions are functions that have access to the request and response objects. They can perform various tasks like executing code, modifying the request and response objects, ending the request-response cycle, and calling the next middleware function. There are several types of middleware: built-in middleware, third-party middleware, and custom middleware.

What is built-in middleware?

Built-in middleware is provided by Express.js itself. Examples include express.json() for parsing JSON requests and express.static() for serving static files.

What about third-party middleware?

Third-party middleware are packages that you can install from npm. Examples include cors for enabling Cross-Origin Resource Sharing and morgan for logging HTTP requests.

Can you give me an example of custom middleware?

Absolutely! Custom middleware is user-defined. For example, you can create a middleware function to log request details like this: app.use((req, res, next) => { console.log(req.method, req.url); next(); });.