Why do we need to use package.json?

Question

I am trying to learn web socket with JavaScript to this site, but I do not understand something that why I need to use package.json. This is my package.json file code:

`{
  "name": "module-name",
  "version": "10.3.1",
  "description": "An example module to illustrate the usage of a package.json",
  "author": "Your Name <[email protected]>",
  "contributors": [{
  "name": "Foo Bar",
  "email": "[email protected]"
}],
  "bin": {
  "module-name": "./bin/module-name"
},
  "scripts": {
    "test": "vows --spec --isolate",
    "start": "node index.js",
    "predeploy": "echo im about to deploy",
    "postdeploy": "echo ive deployed",
    "prepublish": "coffee --bare --compile --output lib/foo src/foo/*.coffee"
  },
  "main": "lib/foo.js",
  "repository": {
  "type": "git",
  "url": "https://github.com/nodejitsu/browsenpm.org"
},
  "bugs": {
  "url": "https://github.com/nodejitsu/browsenpm.org/issues"
},
  "keywords": [
  "nodejitsu",
  "example",
  "browsenpm"
],
  "dependencies": {
    "primus": "*",
    "async": "~0.8.0",
    "express": "4.2.x",
    "winston": "git://github.com/flatiron/winston#master",
    "bigpipe": "bigpipe/pagelet",
    "plates": "https://github.com/flatiron/plates/tarball/master"
  },
  "devDependencies": {
    "vows": "^0.7.0",
    "assume": "<1.0.0 || >=2.3.1 <2.4.5 || >=2.5.2 <3.0.0",
    "pre-commit": "*"
  },
  "preferGlobal": true,
  "private": true,
  "publishConfig": {
  "registry": "https://your-private-hosted-npm.registry.nodejitsu.com"
},
  "subdomain": "foobar",
  "analyze": true,
  "license": "MIT"
}` 

But I do not understand why I need to use it. I tried to find on google but can not find something useful. One more thing, if I create package.json then why I need to write dependencies?

Answer 1

You do not NEED package.json. However, you will most likely want it. As you make larger applications using node.js, you will find that using other people's code is the best solution vs. writing the same thing yourself.

npm has lots of packages that people want to use over and over again. package.json provides a simple way for people to keep track of packages they use in their application.