Creating Routes and Handling Requests with Express.js

When building backend applications with Node.js, handling routes and requests using the built-in HTTP module can quickly become complex.

This is where Express.js makes everything simple.

In this blog, we’ll learn how to create routes and handle requests using Express in a clean and efficient way.

What is Express.js?

Express.js is a lightweight web framework for Node.js.

It helps you:

• Handle routes easily

• Manage requests and responses

• Build APIs faster

In short, Express simplifies backend development by reducing boilerplate code.

Why Express Simplifies Node.js Development

Let’s compare raw Node.js vs Express.js.

❌ Without Express (Raw Node.js)

const http = require('http');

const server = http.createServer((req, res) => {
    if (req.url === '/users' && req.method === 'GET') {
        res.writeHead(200, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({ message: "Get users" }));
    }
});

server.listen(3000);

Problems:

• Manual routing logic

• Hard to scale

• Messy code for multiple routes

With Express.js

const express = require('express');
const app = express();

app.get('/users', (req, res) => {
    res.json({ message: "Get users" });
});

app.listen(3000);

Benefits:

• Clean and readable

• Easy routing

• Less code

Creating Your First Express Server

Step 1: Initialize project

npm init -y

Step 2: Install Express

npm install express

Step 3: Create server

import express from 'express'
const app = express();

app.listen(3000, () => {
     console.log("Server running on port 3000");
});

How Routing Works in Express

Express matches:

• URL (route)

• HTTP method

Then calls the corresponding handler function.

Handling GET Requests

GET is used to retrieve data.

app.get('/users', (req, res) => {
    res.status(200).json({
        message: "List of users"
    });
});

When you open /users, this route gets executed.

Handling POST Requests

POST is used to send data to the server.

app.use(express.json());

app.post('/users', (req, res) => {
    const user = req.body;

    res.status(201).json({
        message: "User created",
        data: user
    });
});

• req.body contains data sent by the client

• We return a response with status 201 Created

Sending Responses in Express

Express provides simple methods to send responses:

• res.send() → Send plain response

• res.json() → Send JSON data

• res.status() → Set HTTP status code

Example:

app.get('/', (req, res) => {
    res.status(200).send("Welcome to Express server");
});

Understanding Routing Structure

Express uses a simple pattern:

app.METHOD(PATH, HANDLER)

Example:

app.get('/products', handler);
app.post('/products', handler);
app.put('/products/:id', handler);
app.delete('/products/:id', handler);

This structure makes your code:

• Predictable

• Scalable

• Easy to maintain

Conclusion

Express.js is one of the most powerful tools for building backend applications with Node.js.

By understanding routing and request handling, you can start building APIs and real-world applications efficiently.