What is the use of router in Express.js ?

Express.js is a powerful framework for node.js. One of the main advantages of this framework is defining different routes or middleware to handle the client’s different incoming requests. In this article, we will discuss, how to use the router in the express.js server.

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. Multiple requests can be easily differentiated with the help of the Router() function in Express.js.This is the advantage of the use of the Router.

Syntax:

express.Router( [options] )

Parameters: This function accepts one optional parameter whose properties are shown below.

• Case-sensitive: This enables case sensitivity.
• mergeParams: It preserves the request params values from the parent router.
• strict: This enables strict routing.

Return Value: This function returns the New Router Object.

Installing Module: Install the module using the following command.

npm install express

Project structure: It will look like this.

Note: The routes folder contains Home.js and login.js file.

Implementation:

Home.js

// Importing express module
const express = require("express")

// Creating express router
const router = express.Router()

// Handling request using router
router.get("/home", (req,res,next) => {
    res.send("This is the homepage request")
})

// Exporting router
module.exports = router

login.js

// Importing the module
const express = require("express")

// Creating express Router
const router = express.Router()

// Handling login request
router.get("/login", (req,res,next) => {
  res.send("This is the login request")
})

module.exports = router

index.js

// Requiring module
const express = require("express")

// Importing all the routes
const homeroute = require("./routes/Home.js")
const loginroute = require("./routes/login")

// Creating express server
const app = express()

// Handling routes request
app.use("/", homeroute)
app.use("/", loginroute)

// Server setup
app.listen((3000), () => {
    console.log("Server is Running")
})

Run index.js using the below command:

node index.js

Output: We will see the following output on the terminal screen.

Server is Running

Now go to http://localhost:3000/login and http://localhost:3000/home, we will see the following output on the browser screen.