DOM NodeList物件length屬性

2019-10-16 23:19:47

DOM NodeList物件length屬性給出節點列表中的節點數。

語法

以下是使用length屬性的語法。

nodelistObject.length

範例

檔案:node.xml 的內容如下 -

<Company> 
   <Employee category = "Technical" id = "firstelement"> 
      <FirstName>Susen</FirstName> 
      <LastName>Su</LastName> 
      <ContactNo>1584567890</ContactNo> 
      <Email>[email protected]</Email> 
   </Employee>  

   <Employee category = "Non-Technical"> 
      <FirstName>Max</FirstName> 
      <LastName>Su</LastName> 
      <ContactNo>1334667898</ContactNo> 
      <Email>[email protected]</Email> 
   </Employee>  

   <Employee category = "Management"> 
      <FirstName>Min</FirstName> 
      <LastName>Su</LastName> 
      <ContactNo>1364562350</ContactNo> 
      <Email>[email protected]</Email> 
   </Employee> 
</Company>

以下範例將XML文件(node.xml)解析為XML DOM物件,並使用length屬性提取長度資訊。

檔案:lenght.html -

<!DOCTYPE html>
<html>
   <meta charset="utf-8"/>
   <head></head>
   <body>
      <script>
         if (window.XMLHttpRequest) {
            xmlhttp = new XMLHttpRequest();
         } else {
            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
         }
         xmlhttp.open("GET","/node_.xml",false);
         xmlhttp.send();
         xmlDoc = xmlhttp.responseXML;

         y = xmlDoc.getElementsByTagName('FirstName');
         document.write("Length of node list: " + y.length);
      </script>
   </body>
</html>

執行上面範例程式碼,得到以下結果 -