Node.js: JavaScript power!!

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Node.js is an event-driven I/O programming environment built on the V8 JavaScript engine (the same one used by Google Chrome).

But what does all this mean? And what can I use it for?

The most basic thing we can build with node.js is a web server (HTTP).

var http = require('http');

http.createServer(function (req, res) {

  res.writeHead(200, {'Content-Type': 'text/plain'});

  res.end('Hello World\n');

}).listen(8124, "127.0.0.1");

With these few lines, we have a web server listening on port 8124 running on our machine and always responding with “Hello World”.

We can also create TCP servers.

To program a node.js server, we use JavaScript as the language, which allows us to avoid many of the complications of other programming languages like C, C++, Python, etc.

As I mentioned, it is completely event-driven, so we won’t have to worry about many tasks that the server handles for us. For example, if we want to respond to a request, we program the response to the “on data” event.

It is very lightweight and fast, and its API is simply fantastic; we have access to system resources (files) and many utilities that will make our programming work easier.

Many of you might wonder: Why do I need to program an HTTP server if there are very powerful options available (Apache, Nginx, etc.)?

The answer is quite simple: they aren’t as lightweight and specific as node.js. With it, we can make use of push technology which allows us to do amazing things like these:

• Chat in the browser: http://chat.nodejs.org/

• We can show the cursor of other website visitors: http://jeffkreeftmeijer.com/2010/experimenting-with-node-js/

• Static file server: http://net.tutsplus.com/tutorials/javascript-ajax/learning-serverside-javascript-with-node-js/

In future posts, we will continue diving deeper into this wonderful project.

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