Backbone.js collection.add()

Backbone.js Collection Add method is used to add a model or array of models to the collection.

Syntax:

Parameter explanation:

models: It contains names of the collection instances, which are need to be added in the collection.

options: It includes model types and adds them to collection instance.

Let's take an example.

See this example:

 <!DOCTYPE html>
   <head>
      <title>Add 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">
         //Consider a model 'Player' containing default values.
         var Player = Backbone.Model.extend({
            defaults: {
               name: "Sachin",
               country:"India"
            }
         });

         //The 'PlayersCollection' is a collection instance and model 'Player' is specified by overriding the 'model' property
         var PlayersCollection = Backbone.Collection.extend({
            model: Player
         });

         //The instances "player1" and "player2" are created for the model "Player"
         var player1 = new Player({name: "Dhoni",  country:"India"});
         var player2 = new Player({name: "Sehwag",  country:"India"});
         var player3 = new Player({name: "Virat",  country:"India"});

         //The add() method adds the models 'player1''player2' and'player3' to the collection instance 'mycollection'
         var mycollection = new PlayersCollection();
         mycollection.add([player1,player2,player3]);

         //The 'length' property deteremines length of the collection
         document.write('Number of added players : ' + mycollection.length);
         </script>
         </body>
      </html>

Test it Now

Output:

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