Introduction

Introduction

• Environment to run javascript outside browser

• Built on Chrome's V8 JS engine

• Full Stack

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Browser JS vs Node JS

Browser	Node.Js
DOM	No DOM
Window	No Window
Interactive Apps	Server Side Apps
No Filesystem	Filesystem
Fragmentation	Versions
ES6 Modules	CommonJS

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Globals

Keyword	Action
__dirname	path to current directory
__filename	file name
require	function to use modules (CommonJs)
module	info about current module (file)
process	info about env where the program is being executed

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Modules

• Encapsulated Code, Only share mininum

• Exported using module.exports

• Imported using require()

Built-in Modules

• OS

• PATH

• FS

• HTTP

Nodemon

• Installed as a global package usually

• Automatically restarts the app when modifying the code

• Included in package.json scripts as nodemon app.js

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Global Package vs NPX

• We should avoid installing dependencies globally since they can cause issues

• We should use NPX (Node Package Runner) to run packages without having to install them locally or globally

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package-lock.json

• When we install a node package of certain version, it also have its own dependencies of specific version

• this file contains the versions of the additional dependencies of the installed packages

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Package versioning (a.b.c)

• Whenever a changes, it means a major change (breaking change)

• b change is a minor change, it is backward compatible

• c change is a patch or bug fix

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