04 - Express App

// Express Framework:
// ==================
// Express is a minimal and flexible Node.js web application framework
// that provides a robust set of features for web and mobile applications.
// With Express, with a myriad of HTTP utility methods 
// and middleware at your disposal, creating a robust API is quick and easy.

// Now, let's create our first Express App
// in my new project's directory, first create package.json file:
    npm init 
// once done, install Express module from npm:
    install i express
// once node_modules folder is created, 
// in index.js file inside your project
// you can use express as used in below file:
    index.js

// Note: in case you run into an error like, port XXXX is already in use, 
// for windows only, do below:
// run command: netstat -a -o -n
// copy the pid of your port from the o/p
// now run command: taskkill /f /pid