Java Script Best Practice Document

    1. Node NPM Setup
        1. npm init — yes   
        2. “engines”:{ “node”:”4.2.1”} 
        3. npm config set save=true
        4. npm config set save-exact=save
    2. Environment Variable — 
        1. nf start
        2. create .env file and entry is available in process.env.PORT
        3. variable declaration always be small case.
    3. Syntax
        1. Linting — jshint —> eslint
        2. Curly braces in same line.
        3. Equality — typeof x !== ‘undefined’
        4. enforce setting in jshint
        5. Variable
        6. functions
    4. Behaviours
        1. Global Variables
        2. Strict Mode 'use strict'
        3. Read Only 
        4. Delete Properties
        5. Duplicates
        6. With Statement
        7. this keyword
    5. Async Pattern
        1. callback
        2. promise, settimeout 
        3. es6