TypeScript problem installing and solution (Permissions) in MacOS High Sierra

Installing TypeScript MacOS

In Terminal:

npm install -g typescript

Error:

npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules
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: '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! Please try running this command again as root/Administrator.

npm ERR! A complete log of this run can be found in:
npm ERR!     /Users/.npm/_logs/2018-05-23T00_50_41_390Z-debug.log

Solution:

sudo npm install -g typescript