First Application with Node.js

Creating a Node.js Application

Step 1: Import the required modules

• Use the require command to load modules needed for the application

  var http = require("http");

  • Loads the HTTP module and stores the returned HTTP instance in the http variable

Step 2: Create the Server

• Execute the http.createServer() method using the http instance created in Step 1

• Use the listen() method to bind with port 8081

• Pass a function with request and response as parameters to http.createServer()

main.js

var http = require("http");

http.createServer(function (request, response) {
    /*
        Send HTTP Header
        HTTP Status: 200 : OK
        Content Type: text/plain
    */
   response.writeHead(200, {'Content-Type': 'text/plain'});

   /*
       Set Response Body to "Hello World"
   */
   response.end("Hello World\n");
}).listen(8081);

console.log("Server running at http://127.0.0.1:8081");

• Creates a web server on port 8081 that always returns "Hello World"

Step 3: Test the Server

Run the server

node main.js

If the server starts successfully, the following text is output

Server running at http://127.0.0.1:8081/

Open http://127.0.0.1:8081/ in a browser to see the following result

image-20200321203909879