npm not installing packages code example

Example 1: how to install any package in node.js

#how to install any specific package in nodejs Application
# Syntex
npm install packagename

# example:
npm install express
npm i express

#if you install globally then type 
npm install express -g

Example 2: install an npm package

npm install package-name

To save as a dependency:
npm install package-name --save

Example 3: install node modules from package.json

npm install (with no args, in package dir)
npm install [<@scope>/]<name>
npm install [<@scope>/]<name>@<tag>
npm install [<@scope>/]<name>@<version>
npm install [<@scope>/]<name>@<version range>
npm install <git-host>:<git-user>/<repo-name>
npm install <git repo url>
npm install <tarball file>
npm install <tarball url>
npm install <folder>

aliases: npm i, npm add
common options: [-P|--save-prod|-D|--save-dev|-O|--save-optional] [-E|--save-exact] [-B|--save-bundle] [--no-save] [--dry-run]

Example 4: how to install npm packages

npm i <package>

Example 5: how to install npm modules

npm install packagename