>challenge 14 documented + updated root readme

Author: nitishdayal

exercises/14 - JavaScript References VS Copying/README.md

@@ -0,0 +1,94 @@
+# Exercise 14: JavaScript Reference vs Copying
+Nitish Dayal, Software & Applications Developer - [Contact](http://nitishdayal.me) 
+Last Commit Date: Dec 19, 2016
+
+No guide necessary! We're learning about JavaScript variable referencing vs.
+ copying. If you want a full-blown explanation, take a look at [chapter 11, section
+ 2 of 'JavaScript: The Definitive Guide'](http://docstore.mik.ua/orelly/webprog/jscript/ch11_02.htm).
+ The easiest way I can summarize the information is that _primitive types are
+ manipulated by value_ and _object types are manipulated by reference_. Still confused?
+ Have **NO** idea what I'm talking about? Carry on, my wayward son; there'll be peace
+ when you are done.
+
+## Manipulating by Value
+
+**Primitive types** are _manipulated by value_. The following types are considered 
+ **primitive types** in JavaScript:
+- String
+- Number
+- Boolean
+- Null
+- Undefined
+
+This means that if we define a variable as a **primitive type**, and then define
+ _another variable_ as the previously defined variable, the second variable
+ will _copy the current value of the first variable_. Any changes to the first
+ variable will not effect the second, and vice versa.
+
+Example:
+
+```JavaScript
+let me = "Nitish"
+let me2 = me
+console.log(me === me2) // true
+
+me2 = "Bob Dylan"
+console.log(me === me2, me, me2) // false, "Nitish", "Bob Dylan"; I'm not Bob Dylan
+
+me = "Not Nitish"
+console.log(me === me2, me, me2) // false, "Not Nitish", "Bob Dylan"
+```
+
+## Manipulating by Reference
+
+**Object types** are _manipulated by reference_. If it's not a primitive type, it's
+ **always** an object. If we're being really technical, almost everything _can be_ 
+ an object in JavaScript, even primitive types (excluding `null` and `undefined`), but
+ let's try not to get hung up on technicalities.
+
+A small list of **object types** in JavaScript:
+- Object
+- Function
+- Array
+- Set
+
+Let's say we declare a variable and define it as an object, then declare _another_
+ variable and define it as the first variable:
+
+```JavaScript
+const me = {name: "Nitish", age: 26}
+const me2 = me
+console.log(me === me2) // true
+```
+
+If we update the property of the object by calling on _either variable_, both variables
+ will reflect that change.
+
+```JavaScript
+me.name = "Not Nitish"
+console.log(me === me2) // true
+console.log(me2) // { name: 'Not Nitish', age: 26 }
+```
+
+This is because `me2` does not copy `me`; it contains a _reference_ to the object
+ defined in `const me`. Any changes applied directly to the object will have an
+ effect on all variables referencing that particular object. So what could we do
+ if we wanted to make a copy of the original object so as not to manipulate the
+ root source of data?
+
+```JavaScript
+const me3 = Object.assign({}, me) // create a new object
+console.log(me3) // {name: 'Not Nitish', age: 26}
+console.log(me === me3) // false! It's a new object instance!
+console.log(me.name === me3.name) // true! The property values are the same!
+me3.name = "Devin"
+console.log(`${me.name}, ${me3.name}`) // 'Not Nitish, Devin'
+```
+
+We have effectively copied the first object and can modify our copy without
+ manipulating the original.
+
+**WARNING: If we copy an object _containing objects_, we are only copying
+ the first level. Anything deeper than that will still be a reference.**
+
+![The More You Know!](http://www.d-toolsblog.com/wp-content/uploads/2008/11/the_more_you_know2.jpg)

exercises/14 - JavaScript References VS Copying/index-FINISHED.html

@@ -1,6 +1,6 @@
 # JavaScript30 - 30 Day JavaScript Challenge
 Nitish Dayal, Software & Applications Developer 
-Last Commit Date: Dec 18, 2016
+Last Commit Date: Dec 19, 2016
 
 > Course created by [Wes Bos](https://github.com/wesbos) 
 > Join the challenge (for free!) here - [JavaScript30](https://javascript30.com/account)
@@ -41,7 +41,7 @@ Completed written guides can be found in the corresponding challenge directory (
 11. [x] ~~[Custom Video Player](./exercises/11\ -\ Custom\ Video\ Player/)~~
 12. [x] ~~[Key Sequence Detection](./exercises/12\ -\ Key\ Sequence\ Detection/)~~
 13. [x] ~~[Slide in on Scroll](./exercises/13\ -\ Slide\ in\ on\ Scroll/)~~
-14. [ ] JavaScript References vs. Copying
+14. [x] ~~[JavaScript References vs. Copying](./exercises/14\ -\ JavaScript\ References\ VS\ Copying)~~
 15. [ ] LocalStorage
 16. [ ] Mouse Move Shadow
 17. [ ] Sort Without Articles