Question: What is node.js?
Node.js is a software for scalable server-side and networking applications.
Node.js applications are written in JavaScript.
It can be run within the Node.js runtime on Mac OS X, Windows and Linux with no changes.
Question: In which language Node.js is written?
C,C++, javaScript.
Question: Who is creater of Node.js?
Ryan Dahl
Question: What is current stable version of Node.js?
6.6.0 Version / 15 September 2016.
Question: How node.js works?
Node.js works on a V8 environment, it is a virtual machine that utilizes JavaScript as its scripting language.
Question: From where we can download Node.js?
http://nodejs.org/download/
Question: What do you mean by the term I/O?
Input/Output
Question: What does event-driven programming?
In event-driven programming, flow of the program is determined by events.
Question: Where Node.js can be used?
- Web applications ( especially real-time web apps )
- Network applications
- Distributed systems
- General purpose application
Question: What is Advantage of Node.js?
Following are advantage of Node.js as compare to other web scripting.
Question: What are two different types of functions in Node.js?
Question: What is Callback in node.js?
It is used to handle the multiple request.
Question: What tool and IDE is used for Node.js?
Question: How to get Post Data in Node.js?
Question: How to make Post request in Node.js?
Question: What is callback hell?
Callback hell refers to heavily nested callbacks that have become unreadable
Question: How to handle the "Unhandled exceptions" in Node.js?
It can be caught at the "Process level" by attaching a handler for uncaughtException event.
Example:
- Faster
- More concurrency user
- Asynchronous
- Least blocks
- Helps to build scalable network programs
Question: What are two different types of functions in Node.js?
- Asynchronous
- Synchronous
Question: What is Callback in node.js?
It is used to handle the multiple request.
Question: What tool and IDE is used for Node.js?
- Atom
- Nodeclipse Enide Studio
- JetBrains WebStorm
- JetBrains IntelliJ IDEA
- Microsoft Visual Studio with TypeScript
- NoFlo – flow-based programming environment integrated with GNOME APIs
Question: How to get Post Data in Node.js?
app.use(express.bodyParser());
app.post('/', function(request, response){
console.log(request.body.user);
});
Question: How to make Post request in Node.js?
var request = require('request');
request.post(
'http://www.example.com/action',
{ form: { key: 'value' } },
function (error, response, body) {
if (!error && response.statusCode == 200) {
console.log(body)
}
}
);
Question: What is callback hell?
Callback hell refers to heavily nested callbacks that have become unreadable
Question: How to handle the "Unhandled exceptions" in Node.js?
It can be caught at the "Process level" by attaching a handler for uncaughtException event.
Example:
process.on('uncaughtException', function(err) {
console.log('Caught exception: ' + err);
});
Question: How to download image from Web?
#Include Important library
var fs = require('fs'),
request = require('request');
#Create a Download Function
var downloadImage = function(uri, filename, callback){
request.head(uri, function(err, res, body){
console.log('content-type:', res.headers['content-type']);
console.log('content-length:', res.headers['content-length']);
request(uri).pipe(fs.createWriteStream(filename)).on('close', callback);
});
};
Use the function in following way:
downloadImage('https://www.google.com/images/srpr/logo3w.png', 'google.png', function(){
console.log('image is downloaded');
});
Question: How to Remove directory which is not empty?
var rimraf = require('rimraf');
rimraf('/some/directory', function () {
console.log('Directory is removed');
});
