unshift

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小牛编辑

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2023-12-01

描述 (Description)

它用于在集合的开头添加指定的模型。

语法 (Syntax)

collection.unshift(models, options)

参数 (Parameters)

models - 它包含集合实例的名称，这些名称将在集合的开头添加。
options - 它包括模型类型并将它们添加到集合实例。

例子 (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">
         //'Player' is a model and contains defualt values for the model
         var Player = Backbone.Model.extend ({
            defaults: {
               name: 'sachin',
               country: 'india'
            }
         });
         //'Players' is an instance of the collection
         var Players = Backbone.Collection.extend ({
            model: Player  //model 'Player' is specified by using model property
         });
         //Here, instantiating models along with "new" keyword and store them in the collection instance
         var player1 = new Player({ id: 1, name: 'gayle', country: 'west indies'});
         var player2 = new Player({ id: 2, name: 'yuvraj', country: 'india'});
         var teamArray = [player1, player2];
         //The unshift() method adds the 'player2' model to the beginning of the collection
         teamArray.unshift(player2);
         //Instantiate new collection by passing in an array of models
         var players = new Players(teamArray);
         document.write(JSON.stringify(players));
      </script>
   </body>
</html>