What is Express - Hands-On Activity

What is Express

📖 Scenario: You want to create a simple web server that can respond to requests from a browser or other clients.

🎯 Goal: Build a basic Express server that listens on a port and responds with a message when accessed.

📋 What You'll Learn

Create a variable called express that requires the Express library

Create an Express app instance called app

Set a port number variable called port with the value 3000

Add a route handler for GET requests to / that sends the text 'Hello from Express!'

Start the server listening on the port variable

💡 Why This Matters

🌍 Real World

Express is used to build websites, APIs, and backend services that respond to user requests over the internet.

💼 Career

Knowing Express is essential for backend web development jobs using Node.js, as it is one of the most popular frameworks.

1

Setup Express and create app

Create a variable called express that requires the Express library and create an Express app instance called app.

Express

// Your code here

Need a hint?

Use require('express') to import Express and call it as a function to create the app.

2

Set the port number

Create a variable called port and set it to 3000.

Express

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

// Your code here

Need a hint?

Use const port = 3000; to set the port number.

3

Add a route handler

Use app.get with path '/' and a callback function with parameters req and res. Inside the callback, use res.send('Hello from Express!') to send the response.

Express

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

const port = 3000;

// Your code here

Need a hint?

Use app.get to handle GET requests to the root path and send a simple text response.

4

Start the server

Use app.listen with the port variable and a callback function that does nothing or logs a message.

Express

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

const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello from Express!');
});

// Your code here

Need a hint?

Use app.listen(port, () => { }) to start the server listening on the port.