Node.js Get Started


Download Node.js

The official Node.js website has installation instructions for Node.js: https://nodejs.org


Getting Started

Once you have downloaded and installed Node.js on your computer, let's try to display "Hello World" in a web browser.

Create a Node.js file named "myfirst.js", and add the following code:

myfirst.js

var http = require('http');

http.createServer(function (req, res) {
  res.writeHead(200, {'Content-Type': 'text/html'});
  res.end('Hello World!');
}).listen(8080);

Save the file on your computer: C:\Users\Your Name\myfirst.js

The code tells the computer to write "Hello World!" if anyone (e.g. a web browser) tries to access your computer on port 8080.

For now, you do not have to understand the code. It will be explained later.


Command Line Interface

Node.js files must be initiated in the "Command Line Interface" program of your computer.

How to open the command line interface on your computer depends on the operating system. For Windows users, press the start button and look for "Command Prompt", or simply write "cmd" in the search field.

Navigate to the folder that contains the file "myfirst.js", the command line interface window should look something like this:

C:\Users\Your Name>_

Initiate the Node.js File

The file you have just created must be initiated by Node.js before any action can take place.

Start your command line interface, write node myfirst.js and hit enter:

Initiate "myfirst.js":

C:\Users\Your Name>node myfirst.js

Now, your computer works as a server!

If anyone tries to access your computer on port 8080, they will get a "Hello World!" message in return!

Start your internet browser, and type in the address: http://localhost:8080


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