What is Node.js?

What is Node.js?

A lot of the confusion for newcomers to Node is misunderstanding exactly what it is. The description on nodejs.org definitely doesn’t help.
An important thing to realize is that Node is not a webserver. By itself it doesn’t do anything. It doesn’t work like Apache. There is no config file where you point it to you HTML files. If you want it to be a HTTP server, you have to write an HTTP server (with the help of its built-in libraries). Node.js is just another way to execute code on your computer. It is simply a JavaScript runtime.

Installing Node
Node.js is very easy to install. If you’re using Windows or Mac, installers are available on the download page.

I’ve Installed Node, now what?
Once installed you’ll have access to a new command called “node”. You can use the node command in two different ways. The first is with no arguments. This will open an interactive shell (REPL: read-eval-print-loop) where you can execute raw JavaScript code.

$ node
> console.log('Hello World');
Hello World
undefined

In the above example I typed “console.log(‘Hello World’)” into the shell and hit enter. Node will then execute that code and we can see our logged message. It also prints “undefined” because it displays the return value of each command and console.log doesn’t return anything.
The other way to run Node is by providing it a JavaScript file to execute. This is almost always how you’ll be using it.
hello.js
In hello.js i have return: console.log(‘Hello World’);

$ node hello.js
Hello World

In this example, I moved the console.log message into a file then passed that file to the node command as an argument. Node then runs the JavaScript in that file and prints “Hello World”.

In next blog i will write how to use NPM(Node package Manager) with node.js.

-By
Nitin Uttarwar
Helical It Solution