DOM - NamedNodeMap 对象项目 - length

属性 length 给出此映射中的节点数。有效子节点索引的范围是 0 到 length-1(含)。

语法

以下是使用 length 属性的语法。

nodemapObject.length

示例

node.xml 内容如下−

<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 length 属性的用法 −

<!DOCTYPE html>
<html>
   <body>
      <script>
         if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
            xmlhttp = new XMLHttpRequest();
         } else {// code for IE6, IE5
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
         }
         xmlhttp.open("GET","/dom/node.xml",false);
         xmlhttp.send();
         xmlDoc = xmlhttp.responseXML;

         x = xmlDoc.getElementsByTagName("Employee");
         document.write("Length is : ");
         document.write(x.item(0).attributes.length);
      </script>
   </body>
</html>