DOM - 属性对象 Attribute - specified

属性specified是一个布尔值，如果属性值在文档中存在，则返回true。

语法

以下是使用specified属性的语法。

attrObject.specified

示例

node.xml的内容如下所示−

<?xml version = "1.0"?>
<Company>
   <Employee category = "Technical">
      <FirstName>Tanmay</FirstName>
      <LastName>Patil</LastName>
      <ContactNo>1234567890</ContactNo>
      <Email>tanmaypatil@xyz.com</Email>
   </Employee>
   
   <Employee category = "Non-Technical">
      <FirstName>Taniya</FirstName>
      <LastName>Mishra</LastName>
      <ContactNo>1234667898</ContactNo>
      <Email>taniyamishra@xyz.com</Email>
   </Employee>
   
   <Employee category = "Management">
      <FirstName>Tanisha</FirstName>
      <LastName>Sharma</LastName>
      <ContactNo>1234562350</ContactNo>
      <Email>tanishasharma@xyz.com</Email>
   </Employee>
</Company>

以下示例演示了name属性的用法 −

<!DOCTYPE html>
<html>
   <head>
      <script>
         function loadXMLDoc(filename) {
            if (window.XMLHttpRequest) {
               xhttp = new XMLHttpRequest();
            } else // code for IE5 and IE6 {
               xhttp = new ActiveXObject("Microsoft.XMLHTTP");
            }
            xhttp.open("GET",filename,false);
            xhttp.send();
            return xhttp.responseXML;
         }
      </script>
   </head>
   <body>
      <script>
         xmlDoc = loadXMLDoc("/dom/node.xml");

         x = xmlDoc.getElementsByTagName('Employee');

         document.write("True if attribute is present else false  : ");
         document.write(x.item(0).attributes[0].specified);
      </script>
   </body>
</html>

执行

将此文件作为domattribute_specified.html保存在服务器路径上（此文件和node.xml应位于服务器上的同一路径）。我们将获得以下输出 −

True if attribute is present else false : true

dom_attribute_object.htm

打印页面