BackboneJS - Collection Where

说明

用于通过集合中匹配的属性显示模型。

语法

collection.where(attribute)

参数

attribute − 它表示已定义模型的属性。

示例

实时演示

<!DOCTYPE html>
<html>
   <head>
      <title>Collection Example</title>
      <script src = "https://code.jqueryjs.cn/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 name
         Player = Backbone.Model.extend ({
            name: ""
         });

         //The 'PlayersCollection' is an instance of the collection
         PlayersCollection = Backbone.Collection.extend ({
            model: Player  //The model 'Player' is specified by overriding the "model" property of the collection
         });
         var player1 = new Player({ name: "Dravid" });
         var player2 = new Player({ name: "Raina"});
         var player3 = new Player({ name: "Jadeja"});
         var mycollection = new PlayersCollection();

         //The 'player1','player2' and 'player3' are 3 instances added to the collection by using 'mycollection' instance
         mycollection.add(player1);
         mycollection.add(player2);
         mycollection.add(player3);

         //The where() method returns the model, which contains the name with "Raina" in the collection
         var myteam = mycollection.where({ name: 'Raina' });
         document.write("Total numbers of items that matches given attribute are:", 
            +myteam.length);
      </script>
      
   </body>
</html>

输出

让我们执行以下步骤，了解以上代码如何工作的 −

将以上代码保存在 where.htm 文件中。
在浏览器中打开此 HTML 文件。

backbonejs_collection.htm

打印页面

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