hasChanged

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小牛编辑

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2023-12-01

描述 (Description)

如果属性自上次set发生更改，则返回true。

语法 (Syntax)

model.hasChanged(attribute)

参数 (Parameters)

attribute - 它定义模型的属性。

例子 (Example)

<!DOCTYPE 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 person = new Backbone.Model({
            name: 'john'
         });
         document.write('Has name changed (before set) = ' + person.hasChanged());
         person.set('name', 'smith', {silent: true});
         document.write('<br>Has name changed (after set) =' + 
            person.hasChanged());
      </script>
   </head>
   <body></body>
</html>