The res.redirect() function redirects to the URL derived from the specified path, with specified status, an integer (positive) which corresponds to an HTTP status code. The default status is “302 Found”....

The res.sendFile() function transfers the file at the given path and it sets the Content-Type response HTTP header field based on the filename extension....

The res.render() function in Express is used to render a view and sends the rendered HTML string to the client....

The express.json() function is a built-in middleware function in Express. It parses incoming requests with JSON payloads and is based on body-parser....

The req.params property is an object containing properties mapped to the named route “parameters”. For example, if you have the route /student/:id, then the “id” property is available as req.params.id. This object defaults to {}....

The res.json() function sends a JSON response. This method sends a response (with the correct content-type) that is the parameter converted to a JSON string using the JSON.stringify() method....

The res.send() function sends the HTTP response. The body parameter can be a String or a Buffer object or an object or an Array....

The express.Router() function is used to create a new router object. This function is used when you want to create a new router object in your program to handle requests....

app.listen() in Express is like telling your app to start listening for visitors on a specific address and port, much like how Node listens for connections. The app, created by `express()`, is just a handy function that handles different types of requests, making it easy to serve both HTTP and HTTPS versions of your app without extra complexity....

The req.body property contains key-value pairs of data submitted in the request body. By default, it is undefined and is populated when you use a middleware called body-parsing such as express.urlencoded() or express.json()....

The express.urlencoded() function is a built-in middleware function in Express. It parses incoming requests with URL-encoded payloads and is based on a body parser....

Creating an Express.js application involves several steps that guide you through setting up a basic server to handle complex routes and middleware. Express.js is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications. Here’s a comprehensive guide to get you started with your Express.js application....