node js

1. Objective
What is Node JS?
Why Node JS?
Setup NodeJS
Node Package Manager
Hello World Application

2. What is Node.js?
 Created by Ryan Dahl in 2009 in Joyent
 Server-side JavaScript Framework
 Uses V8 is an open source JavaScript engine developed
by Google. Its written in C++ and is used in Google
Chrome Browser
 Event-driven with Non-blocking I/O
 Single threaded

3. Why Node.js?
1. Free from deadlocking Process
2. Event Driven Programming
3. Nonblocking I/O
4. Easy to build the scalable application
5. Same language(JS) for both backend and frontend
6. Large open source package System(NPM)
7. Hosting
8. A big corporate is taking care of project(Joyent)
9. Easy to build real-time application

4. Blocking Vs NonBlocking

5. Node JS Installation
Node JS installation can be done in four ways.
First of all, Go to the Node JS website which is
https://nodejs.org/en/download.
1. Precompiled Binary
2. Installer
3. Source Code
4. NVM (Node Version Manager)

6. Installation using NVM
NodeJS Installation command using the NVM:
NVM install <version_number>
This command will check the stable version based on the version
number and install the stable version.

7. Node JS basic commands
To check the version of install NodeJS
node -v
To change the NodeJS version
NVM use <version_number>
To run JavaScript code right from your terminal, you can use
the – e option
node -e 'console.log(3 + 2)'
Or
node -p '3 + 2'

8. NPM
NPM is a package manager for Node JS.NPM is the pre-build
libraries for Node JS.
Whenever you install Node JS, npm will automatically install in
your system.
NPM.inc is the company that host and maintains it.It is available
at https://npmjs.com.
To get the npm version, following command is used:
npm - v

9. Node.JS – as an interactive shell
> node
3 + 4
7
> true != false
true