Express.js

For install Express in ubuntu via npm (Follow following steps)

First open terminal by 'ctrl + alt + t'

1. Check nodejs is installed or not by command :- node -v
2. Inter following path into terminal :- cd /var/www/html
3. Create new folder (manually) or by command line :- mkdir nodeTest
4. Enter in "nodeTest" folder :- cd nodeTest
5. Create 'package.json' :- npm init //initialize node project (nodeTest)
6. install Express :- sudo npm install express --save

Now open the 'nodeTest' folder from following path in your system :- /var/www/html/nodeTest

Now create :- index.js

index.js

var express = required("express");
var app = express();

app.get("/", function (req, res) {
    res.send(" Welcome Node js ");
});  

app.listen(8000, function () {
    console.log("Node server is runing on port 8000...");
});

Runnig node server by terminal command :- node index.js

Now check url :- "localhost:8000"