has

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小牛编辑

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2023-12-01

描述 (Description)

如果将属性设置为非null或非undefined值，则此方法返回true 。

语法 (Syntax)

model.has(attribute)

参数 (Parameters)

attribute - 属性定义已创建模型的属性。

例子 (Example)

<!DOCTYPE html>
<html>
   <head>
      <title> Model 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>
      <script type = "text/javascript">
         var Company = Backbone.Model.extend();
         var company = new Company();
         company.set({ Name: "xnip", comp_site:"www.xnip.cn"});
         if(company.has('comp_site')) {
            document.write("The model Company has site: True");
         } else {
            document.write("The model Company has site: False");
         }
      </script>
   </head>
   <body></body>
</html>