npm install and package.json

If you have node installed then opening the command prompt, navigating to any folder, and then typing...

npm install

 
 

...will prompt node to try to find a file in the folder called "package.json" of which the contents might look like so:

{
   "name": "Whatever",
   "version": "0.1.0",
   "devDependencies": {
      "grunt": "~0.4.1",
      "grunt-contrib-jshint": "~0.1.1",
      "grunt-contrib-nodeunit": "~0.1.2",
      "grunt-contrib-copy": "~0.4.1",
      "grunt-contrib-clean": "~0.4.1",
      "grunt-mocha": "~0.3.4",
      "grunt-cli": "~0.1.9",
      "grunt-jsduck": "~0.1.4"
   }
}

 
 

Node will use devDependencies as a list of packages to have. If any of the packages are not yet installed, it will install those packages.