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shevchenkonik /
Last active Jun 14, 2019
The difference between dependencies and devDependencies in Node Package Manager

When using NPM (Node Package Manager) you must see file package.json. In this file described information about package and you can see a list of all dependencies. Dependencies are divided into two types: dependencies and devDependencies. The difference between these two types is dependencies are packages that needed for production environment while devDependencies are packages which are only needed for local environment & test's. Dependencies (for runtime): Axios, Express, React, etc. DevDependencies (for local environment & tests): Babel, Webpack, ESLint, Jest, etc. To add dependencies to your project you need to do an npm install -save (shortcut: npm i -S) and if you want to add devDependencies you can run the following command: javascript npm install --save-dev (shortcut: javascript npm i -D).

View IIFE.js
var outputValue = 'placebo';
(function() {
console.log(outputValue); // undefined
var outputValue = 'radiohead';