Node.js Basics

Node.js Basics

• 1.
  Objective What is NodeJS? 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. Freefrom 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 NodeJS 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 NodeJSInstallation 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 basiccommands 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 apackage 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 – asan interactive shell > node 3 + 4 7 > true != false true
• 10.
  Node.JS – asan interactive shell > node 3 + 4 7 > true != false true