How Node.js differs from browser JavaScript in Node.js - Try It Yourself

Understanding How Node.js Differs from Browser JavaScript

📖 Scenario: You are learning JavaScript and want to understand the differences between running JavaScript in a browser and running it in Node.js on your computer.

🎯 Goal: Create a simple Node.js script that shows how to use a Node.js-specific feature and a browser-specific feature separately, so you can see the difference clearly.

📋 What You'll Learn

Create a variable called message with the value 'Hello from Node.js'

Create a variable called isBrowser that checks if the global window object exists

Use an if statement to print message if running in Node.js (when isBrowser is false)

Add a comment explaining that window is only available in browsers

💡 Why This Matters

🌍 Real World

Developers often need to write JavaScript that works differently in browsers and Node.js environments. Detecting the environment helps run the right code.

💼 Career

Understanding environment differences is key for full-stack developers and anyone working with JavaScript outside the browser.

1

Create a message variable

Create a variable called message and set it to the string 'Hello from Node.js'.

Node.js

// Create a variable called message with the value 'Hello from Node.js'
// Your code here

Need a hint?

Use const to create a variable that does not change.

2

Check if running in a browser

Create a variable called isBrowser that is true if the global window object exists, otherwise false. Use typeof window !== 'undefined' to check.

Node.js

const message = 'Hello from Node.js';
// Create a variable called isBrowser to check if window exists
// Your code here

Need a hint?

Use typeof to safely check if window exists without causing errors.

3

Print message only in Node.js

Write an if statement that prints message only if isBrowser is false (meaning the code runs in Node.js). Use console.log(message) inside the if block.

Node.js

const message = 'Hello from Node.js';
const isBrowser = typeof window !== 'undefined';
// Add an if statement to print message only if not in browser
// Your code here

Need a hint?

Use !isBrowser to check if you are not in a browser.

4

Add a comment about window object

Add a comment above the isBrowser variable explaining that the window object is only available in browsers.

Node.js

// Add a comment explaining that window is only in browsers
const message = 'Hello from Node.js';
const isBrowser = typeof window !== 'undefined';

if (!isBrowser) {
    console.log(message);
}

Need a hint?

Write a simple comment starting with // above the isBrowser line.