BackboneJS collection.shift()方法

从集合中删除的第一个项目。

语法

collection.shift(options)

参数:

  • options: 包括要从集合中删除模型类型。

示例

<!DOCTYPE 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
          });

          //Instantiate the 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];

          document.write("<b>Before using shift method:</b>",JSON.stringify(teamArray));
          //The shift() method removes the model 'player1' from the collection
          teamArray.shift();

          //The 'players' is the collection instance and contains array of models
          var players = new Players(teamArray);
          document.write("<br><b>After using shift method:</b>",JSON.stringify(players));
      </script >
   </body>
</html>

输出

让我们进行以下步骤来看看上面的代码工作:

  • 保存上述代码在文件shift.html

  • 在浏览器打开这个HTML文件。