Creating Routes and Handling Requests with Express
When we building web applications using Node.js, writing code using the built-in HTTP module can be complex and repetitive.
To make development easier, we use Express.js.
1. What is Express.js?
Express.js is a web framework for Node.js.
It helps to:
Create servers easily
Handle requests and responses
Manage routes (URLs)
Build web applications faster
Why Developers Prefer Express
Simple and clean syntax
Easy routing system
Saves time
Widely used in real projects
2. Why Express Simplifies Node.js Development
Without Express, we have to use the HTTP module, which requires more code.
Example: Raw Node.js Server
import http from 'node:http'
const server = http.createServer((req, res) => {
if (req.url === "/") {
res.end("Home Page");
}
});
server.listen(3000);
Problems:
More manual work
Hard to manage routes
Less readable
Example: Express Server
import express from 'express';
const app = express();
app.get("/", (req, res) => {
res.send("Home Page");
});
app.listen(3000);
Benefits:
Less code
Easy routing
Clean and readable
3. Creating First Express Server
Step 1: Install Express
npm install express
Step 2: Create Server
import express from 'express';
const app = express();
app.listen(3000, () => {
console.log("Server running on port 3000");
});
4. Handling GET Requests
GET requests are used to fetch data.
app.get("/", (req, res) => {
res.send("Welcome to Home Page");
});
app.get("/about", (req, res) => {
res.send("About Page");
});
Each URL is called a route
Routing Concept
Routing means: "What should happen when a user visits a specific URL?"
Example:
/→ Home page/about→ About page/contact→ Contact page
5. Handling POST Requests
POST requests are used to send data to the server.
app.use(express.json());
app.post("/data", (req, res) => {
console.log(req.body);
res.send("Data received");
});
Used in:
Forms
APIs
Login systems
6. Sending Responses
Express provides simple methods to send responses:
res.send("Hello"); // send text
res.json({ name: "John" }); // send JSON
res.status(200).send("OK"); // status + message
Request → Response Flow
Client Request
↓
Route(app.get/app.post)
↓
Route Handler Function
↓
Response(res.send)
↓
Client Receives Data
Simple Example
const express = require("express");
const app = express();
app.get("/", (req, res) => {
res.send("Welcome");
});
app.get("/user", (req, res) => {
res.json({ name: "Rahul", age: 20 });
});
app.post("/login", (req, res) => {
res.send("Login successful");
});
app.listen(3000);
Conclusion
Express.js makes working with Node.js much easier. It simplifies server creation, routing, and handling requests.
If you want to build web applications quickly and efficiently, Express is a great choice.
Express turns complex server code into simple and readable code.
