What is Express.js?
Express.js is a web application framework for Node.js that provides a set of features and tools for building web applications and APIs. It simplifies the process of handling HTTP requests and responses, routing, middleware, and other common tasks in web development.
How do you install Express.js?
You can install Express.js using npm (Node Package Manager) by running the command npm install express.
npm install express
- What is routing in Express.js?
- Routing in Express.js refers to the process of mapping HTTP requests to specific endpoints (URL paths) and defining how the server should respond to each request. Express provides methods for defining routes and specifying the corresponding request handlers (callbacks).
How do you define a route in Express.js?
To define a route in Express.js, you use the app.METHOD() functions, where METHOD is the HTTP method (e.g., GET, POST, PUT, DELETE). For example:
app.get('/', function(req, res) {
res.send('Hello World!');
});
What is middleware in Express.js?
- Middleware in Express.js are functions that have access to the request and response objects and can modify them or perform additional tasks before passing control to the next middleware function in the stack. Middleware functions can be used for tasks such as logging, authentication, error handling, and parsing request bodies.
