thecodeduchess/lang_notes

#Objects in Javascript VS Ruby

##Basic Initialization

function Book(title, author, numPages) {
  this.title = title;
  this.author = author;
  this.numPages = numPages;
}

var book = new Book("Harry Potter", "J.K. Rowling", 800);

---

class Book

 	def initialize(title, author, num_pages)
	 	@title = title
	 	@author = author
	 	@num_pages = num_pages
	end
end

	book = Book.new("Harry Potter", "J.K. Rowling", 800)

##Hash Initialization

function Book(config) {
  this.title = config.title;
  this.author = config.author;
  this.numPages = config.numPages;
}

var book = new Book({title: "Harry Potter", author: "J.K. Rowling", numPages: 800});

---

class Book
	attr_reader :title, :author, :num_pages
	def initialize(attributes)
		@title = attributes.fetch(title)
		@author = attirbutes.fetch(author)
		@num_pages = attributes.fetch(num_pages)
	end
end


book = Book.new({title: "Harry Potter", author: "J.K. Rowling", num_pages: 800})

This is the same as:

book = Book.new({:title => "Harry Potter", :author => "J.K. Rowling", :num_pages => 800}) 

The hash rockets are used in older versions of Ruby, but since 1.9 I believe, the colons in front are valid. Of course it's much easier to distinguish between symbols and the hash if you use the hash rocket.

You will find in a lot of rails app that they use a colon instead of hash rocket.

#Extending objects in javascript

This is a little more advanced so you don't need to worry about it right now.

IT's mostly here for my own reference.

// The constructor function

function PaperBack(title, author, numPages, cover) {
  Book.call(this, title, author, numPages);
  this.cover = cover;
}


// Extending the Book object

PaperBack.prototype = Object.create(Book.prototype);


// A new method on this object

PaperBack.prototype.burn = function() {
  console.log("You burned " + this.numPages + " pages!");
  this.numPages = 0;
}


// Instantiating a new object

var paperback = new PaperBack("1984", "George Orwell", 250, "cover.jpg");

paperback.read();
paperback.burn();