Constructor Pattern

	Constructor Pattern
	A constructor is used to create specific types of objects -both preparing the object for use and accepting arguments which a constructor can use to set properties and methods when the object first created.
	Object Creation
	The three common ways to create new objects in JavaScript are as follows:
	var newObject = {};
	var newObject = Object.create( Object.prototype );
	var newObject = new Object();
	There are then four ways in which keys and values can then be assigned to an object:
	a) Dot syntax
	//Set Properties
	newObject.someKey = "Hello World";
	//Get Properties
	var value = newObject.someKey;
	b) Square bracket syntax
	//Set Properties
	newObject["someKey"] = "Hello World";
	//Get Properties
	var value = newObject["someKey"];
	c) Object.defineProperty
	//Set Properties
	Object.defineProperty( newObject, "someKey", {
	value: "more control",
	writable: true,
	enumerable: true,
	configurable: true
	});
	OR
	var defineProp = function ( obj, key, value){
	var config = {
	value: value,
	writable:true,
	enumerable: true,
	configurable: true,
	};
	Object.defineProperty( obj, key, config );
	So in order to use this we have to create an empty "person" object
	var person = Object.create(Object.prototype);
	//Populate the object with properties
	defineProp( person, "car". "Delorean" );
	defineProp(person, "dateOfBirth", "1981" );
	defineProp( person, "hasBeard", false );
	console.log(person);
	Constructors With Prototypes
	When we call a constructor to create an object then we can access all the constructor's properties through prototype.
	function Car( model, year, miles ) {
	this.model = model;
	this.year = year;
	this.miles = miles;
	};
	// Note here that we are using Object.prototype.newMethod rather than
	// Object.prototype so as to avoid redefining the prototype object
	Car.prototype.toString = function () {
	return this.model + " has done " + this.miles + " miles";
	};
	// Usage:
	var civic = new Car( "Honda Civic", 2009, 20000 );
	var mondeo = new Car( "Ford Mondeo", 2010, 5000 );
	console.log( civic.toString() );
	console.log( mondeo.toString() );
	Above, a single instance of toString() will now be shared between all of the Car objects