Backbone.js collection.comparator()

In Backbone.js, the comparator property is used to maintain the collection in the sorted order. By default, there is no comparator for a collection.

Syntax:

Let's take an example.

See this example:

<!DOCTYPE html>
   <head>
      <title>Comparator Collection Example</title>
         <script src="https://code.jquery.com/jquery-2.1.3.min.js" type="text/javascript"></script>
         <script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.2/underscore-min.js" type="text/javascript"></script>
         <script src="https://cdnjs.cloudflare.com/ajax/libs/backbone.js/1.1.2/backbone-min.js" type="text/javascript"></script>
   </head>
   <body>
      <script type="text/javascript">
         var MyModel = Backbone.Model.extend();      //'LangNames' is a model name

         //'mydata' variable contains values to be displayed in sorted order
         var mydata = [
            {id:4, name: 'Sachin Tendulkar'},
            {id:2, name: 'Rahul Dravid'},
            {id:3, name: 'Saurav Ganguly'}
         ];

         //'myval' is a collection instance and includes array of values stored in 'mydata' variable
         var myval = new Backbone.Collection(mydata,{
            model:MyModel,   //The model 'MyModel' is specified by overriding the "model" property
            comparator: 'name'   //The 'comparator' maintain the collection in sorted order
         });

         //Here, displaying the array of values using collection instance 'myval' and 'models' method
          document.write("The sorted (based on name) order of collection: ",
            JSON.stringify(myval)
         );
      </script>
   </body>
</html>

Test it Now

Output:

Save the above code in comparator.html file and open this file in a new browser.