Vue-Cli won't install - node.js

Question

I have node 11.2.0
Keep receiving this error.
Andrews-MacBook-Pro:vueTutorial aharris$ npm install -g #vue/cli
npm WARN deprecated hoek#5.0.4: This version is no longer maintained. Please upgrade to the latest version.
npm WARN deprecated cross-spawn-async#2.2.5: cross-spawn no longer requires a build toolchain, use it instead
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules
npm WARN #apollographql/apollo-upload-server#5.0.3 requires a peer of graphql#^0.13.1 but none is installed. You must install peer dependencies yourself.
npm ERR! path /usr/local/lib/node_modules
npm ERR! code EACCES
npm ERR! errno -13
npm ERR! syscall access
npm ERR! Error: EACCES: permission denied, access '/usr/local/lib/node_modules'
npm ERR! { [Error: EACCES: permission denied, access '/usr/local/lib/node_modules']
npm ERR! stack:
npm ERR! "Error: EACCES: permission denied, access '/usr/local/lib/node_modules'",
npm ERR! errno: -13,
npm ERR! code: 'EACCES',
npm ERR! syscall: 'access',
npm ERR! path: '/usr/local/lib/node_modules' }
npm ERR!
npm ERR! The operation was rejected by your operating system.
npm ERR! It is likely you do not have the permissions to access this file as the current user
npm ERR!
npm ERR! If you believe this might be a permissions issue, please double-check the
npm ERR! permissions of the file and its containing directories, or try running
npm ERR! the command again as root/Administrator (though this is not recommended).
npm ERR! A complete log of this run can be found in:
npm ERR! /Users/aharris/.npm/_logs/2018-11-25T18_43_42_502Z-debug.log

Answer 1

You are facing the problem of file permissions.
-g parameter of npm means "globally", which will install those file in the system directory, specifically in your computer /usr/local/lib/node_modules, where the owner is possibly root and with permission rwxr-xr-x, means those who is not root will have no permission to write.
Then, you may use sudo to get this permission, or just like NPM modules won't install globally without sudo said, set the npm prefix into the path where you have permissions:
$ npm config set prefix '~/.npm-packages'

Answer 2

All you need to do is run the same command with sudo before it,
sudo npm install -g #vue/cli
and you'll be prompted for the admin password.