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BackboneJS - Collection Length
Description
It is a property that counts the number of models in the collection.
Syntax
collection.length
Example
<!DOCTYPE html> <html> <head> <title>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"> //'Cities' is a model and contains defualt value for the model var Cities = Backbone.Model.extend ({ defaults: { city: "Hyderabad" } }); //'CityCollection' is an instance of the collection var CityCollection = Backbone.Collection.extend ({ model: Cities //model 'Cities' is specified by using model property }); //The add() method adds the models 'city1', 'city2' and 'city3' to the collection instance 'mycollection' var city1 = new Cities({city: "Banglore"}); var city2 = new Cities({city: "Delhi"}); var city3 = new Cities({city: "Mumbai"}); var mycollection = new CityCollection(); mycollection.add([city1,city2,city3]); document.write('Number of models in collection : ' + mycollection.length); </script> </body> </html>
Output
Let us carry out the following steps to see how the above code works −
Save the above code in the length.htm file.
Open this HTML file in a browser.
backbonejs_collection.htm
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