Basic Routing Fundamentals
Learn to define and handle routes in Express.js using different HTTP methods.
Routing determines how a web application handles incoming requests based on the requested URL and HTTP method. Think of it like a traffic system, directing users to the right destination. For example, when someone visits http://example.com/welcome, the application must decide whether to display a web page or return data.
In Express.js, a route defines how an application processes incoming requests. A route consists of three key parts:
Path (URL): This is the requested resource.
HTTP method: This specifies the type of request (
GET,POST,PUT, orDELETE) and the intended action (retrieving, creating, updating, or deleting data).Route handler: This function processes the request and sends a response.
Here is an example of a route that handles GET requests at the /welcome path and responds with 'Welcome to Express.js!'.
app.get('/welcome', (req, res) => {res.send('Welcome to Express.js routing!');});
Each route corresponds to an endpoint—a specific combination of a URL path and an HTTP method that clients use to interact with the application. An application typically includes multiple endpoints, each responsible for handling a specific task—like retrieving user profiles, submitting form data, or updating records in a database.
Understanding route handlers in Express.js
A route handler is a function that processes incoming requests and sends responses. Every route in Express.js must have a handler that determines how the application responds.
For example, in the following route:
app.get('/greeting', (req, res) => {res.send('Hello, welcome to our API!');});
Explanation: