Routing in Expressjs

Introduction

Routing refers to how an application’s endpoints (URIs) respond to client requests. Expressjs official Docs

You define routing using express app object corresponding HTTP methods POST and GET method.

For example

The following code shows an example of a very basic route.

const express = require('express')
const app = express() // express object

// respond with "hello world" when a GET request is made to the homepage
app.get('/', function (req, res) {
  res.send('hello world')
})

Route Methods

A route method is derived from one of the HTTP methods and is attached and called on app object, an instance of the express class.

GET and POST Methods to the root off the app:

// GET method route
app.get('/', function (req, res) {
  res.send('GET request to the homepage')
})

// POST method route
app.post('/', function (req, res) {
  res.send('POST request to the homepage')
})

Route Paths

These routes defined in the above code snippet will map to:
http://localhost:3000/ when app is run locally and matching depends on whether client uses POST or GET method and vice versa.

// GET method route
app.get('/about', function (req, res) {
  res.send('about route')
})
// 

The above route matches to http://localhost:3000/about when the app is run locally.

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Summary

We've learn't how to define routes in a very basic approach. In the next article, we shall learn about Route Params