Basic of Node js

What is node js?

• Node js is an JavaScript runtime environment that executes JavaScript code outside of a web browser.
• It is built on the Google Chrome V8 JavaScript runtime engine. The same engine which compile our js code on browser

Why node js?

• If you like to code backend in js then node js is your friend
• Modules/Packages: Node.js has npm, a node package manager, with a library of over 350,000 packages to help get your project or application off the ground with efficiency and ease.
• Non blocking I/O model / Event Driven

What can node js do ? and example

• API's and servers
• Databases (yes some DB's are built in Node)
• CLI'sBuild Tools
• AutomationsBasic
• ScriptingGPU shopping bots 👀

Global in node js

In node js it can be understood as the window in browser.what is defined globally for that we don't need to import any packages .

Example :- __dirname ,__filename,Process,Export,Import ,require

Module

What are modules ?

• module is pre written chunk of code and it can be a single file or more than one file that you use in your code
• Module are two type :- Internal module, External module

What is internal module ?

• Internal module are the built in module by node js and we don't need to install it

Like fs module ,url etc

Importing module

• There are two method you can import or use javascript code written in different file / folder
• Common js - const name = require('file/folder relative path' )
• Module way :-import('file/folder relative path' )

What is fs module ?

• This is the internal module provide by node js to interact with files
• Some of the method are :-
• fs module for read and write

1. readFile
2. writeFile
3. readFileSync
4. writeFileSync

Package

• What is packages and what is the use of it?
• Packages are the collection of module .
• Which perform some specified task
• Like express is backend framework ,open ,body-parser parse the incoming request etc
• 💡 npm (node package manager ) ut manage the different version of pacakge
• Why do we need package.json file and how to create ?

npm init // while running in terminal  it ask a bunch of questions 
and you want to ignore  those questions just type
npm init -y         

Package.json

whenever we work on the node js ,it provide all the information about pacakges , version and script to run in terminal. etc

How to install packages ?

npm install pacakge-name
or 
npm i pacakge-name         

How to uninstall package?

npm uninstall pacakge-name
or 
npm i pacakge-name        

Hopefully you have learnt something and i would like listen from you any suge