Installing Nodejs and NPM

Nodejs provides JavaScript with a way to optimise single threaded and single CPU core processing. 
NPM is a package manager to deliver applications. Its like yum on Centos linux.

In this case, I am installing Cordova for Android development on Centos 7.4 and it required nodejs along with npm. Hence, this article came along the way.

Step 1: Install Epel repository

$ sudo yum install epel-release  
$ sudo yum info nodejs
It shows nodejs version 6.12.3

Step 2: Install nodejs

Install the development environment then nodejs. This will install together the npm (version 3.10.10)
$ sudo yum --setopt=group_package_types=mandatory,default,optional groupinstall "Development Tools"
$ sudo yum install nodejs

Check installed version
$ node -v
$ npm -v

Step 3: Run Hello World

Create this script and name it as helloworld.js to test on a command line and the web browser.

var http = require('http');

http.createServer(function (req, res) {
    res.writeHead(200, {'Content-Type': 'text/html'});
    res.end('<p>This is <b>Hello World</b></p>');
}).listen(8080);
console.log('This example is my world!');

At a command line, type
$ node helloworld.js

This should display the output on the command line.
Next, open a web browser and type the following url

localhost:8080

Continue with Cordova installation from previous article.