That covers all the core functionality of Model, but before we move on to explore Collections, some of the convenience methods of Model are worth mentioning. In addition to requiring Underscore, Backbone alo incorporates many Underscore methods into its classes as shortcut methods, and Model is a perfect example. The main advantage of using these built-in shortcut methods, besides being a bit more readable, is that they operate on the Model's attributes rather than the Model itself.

For instance, Underscore has a method called keys, which you can use to get all the keys on an object. You can use this method directly to get all the keys of a Model's attributes, as follows:

var book = new Backbone.Model({pages: 20, title: 'Short Title'};
var attributeKeys = _.keys(book.attributes);
alert(attributeKeys); // alerts ['pages', 'title']

However, if you use Model's version of that same method instead, you can simplify your code slightly and make it slightly more readable:

var attributeKeys =  book.keys();
alert(attributeKeys); // alerts ['pages', 'title'];

There are a total of six of these methods on Model, and while we don't have time to explain all of them in this book, here's a brief summary of what each one does: