পর্যালোচনা: অবজেক্ট-অরিয়েন্টেড ডিজাইন

var Book = function(title, author, numPages) {
  this.title = title;
  this.author = author;
  this.numPages = numPages;
  this.currentPage = 0;
};

var book = new Book("Robot Dreams", "Isaac Asimov", 320);

println("I loved reading " + book.title); // Robot Dreams পড়তে আমি পছন্দ করতাম
println(book.author + " is my fav author"); // "Isaac Asimov" আমার প্রিয় লেখক

var Book = function(title, author, numPages) {
};
var book = new Book("Little Brother", "Cory Doctorow", 380);
println("I loved reading " + book.title); // I loved reading undefined
println(book.author + " is my fav author"); // undefined is my favorite author

Book.prototype.readItAll = function() {
  this.currentPage = this.numPages;
  println("You read " + this.numPages + " pages!");
};

var book = new Book("Animal Farm", "George Orwell", 112);
book.readItAll(); // 112 পৃষ্ঠাই পড়া হয়েছে!

var pirate = new Book("Pirate Cinema", "Cory Doctorow", 384);
var giver = new Book("The Giver", "Lois Lowry", 179);
var tuck = new Book("Tuck Everlasting", "Natalie Babbit", 144);

pirate.readItAll(); // তুমি 384 পৃষ্ঠায় পড়ে ফেলেছ!
giver.readItAll(); // তুমি 179 পৃষ্ঠায় পড়ে ফেলেছ!
tuck.readItAll(); // তুমি 144 পৃষ্ঠায় পড়ে ফেলেছ!

var PaperBack = function(title, author, numPages, cover) {
  // ...
}

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

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

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

PaperBack.prototype.burn = function() {
  println("Omg, you burnt all " + this.numPages + " pages");
  this.numPages = 0;
};

var calvin = new PaperBack("The Essential Calvin & Hobbes", "Bill Watterson", 256, "http://ecx.images-amazon.com/images/I/61M41hxr0zL.jpg");

calvin.readItAll(); // তুমি 256 পৃষ্ঠায় পড়ে ফেলেছ!
calvin.burn(); // ওহো, তুমি 256 পৃষ্ঠায় পুড়িয়ে ফেলেছ!