slice

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小牛编辑

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2023-12-01

描述 (Description)

它返回集合模型中元素的浅表副本。

语法 (Syntax)

collection.slice(begin, end)

参数 (Parameters)

begin - 它指定从哪里开始提取元素。
end - 它指定结束元素提取的位置。

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">
         var City = Backbone.Model.extend();
         //The variable "Cities" contains the elements which are to be displayed when 'slice()' method is called
         var Cities = ['NewYork', 'Sydney', 'Durban', 'Lancashire', 'Kent'];
         //The collection instance "cities" uses the "Cities" variable to represent the model elements in 
         //the collection
         var cities = new Backbone.Collection (Cities, {
            model:City
         });
         //The slice(1,4) method begins the element extraction at index "1" and ends the extraction of elements 
         //up to the index "4"
         var mycity = Cities.slice(1,4);
         //The 'length' property specifies the total number of sliced elements between 1 and 4
         document.write("Number of Cities:", +mycity.length);
         document.write("<br>");
         document.write(JSON.stringify(mycity));
      </script>
   </body>
</html>