how to extract values from an XML document using Javascript

I开发者_开发问答 am trying to extract values from the xml document and print them. I also want to count the number of children(child nodes) each node has.That is the first tag has 2 child and second tag has 3.

THIS IS THE XML DOCUMENT

<?xml version="1.0" ?> 
  <A>
  <a1>a1</a1> 
  <a2>a2</a2> 
  <B>
  <C>2</C> 
  <C>3</C> 
  </B>
  <B>
  <C>4</C> 
  <C>5</C> 
  <C>6</C>
  </B>
  </A>

THIS IS MY JAVASCRIPT DOCUMENT

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","extractexample.xml",false);
xmlhttp.send();
xmlDoc=xmlhttp.responseXML;
xmlObj=xmlDoc.documentElement;
document.write(xmlDoc.getElementsByTagName("B")[0].childNodes[0].nodeValue);

Element.childNodes method returns all types of nodes, including whitespace textnodes. It may not be what you want. If you only care for the number of child elements, use childElementCount.

var b = xmlDoc.getElementsByTagName("B")[0];
alert(b.childElementCount); //should output 2

I haven't tried in IE, it may not work. Else, if you want a the element list, use children children not supported on non HTML doc. You can try this function:

function getChildren(element) {
  var nodes = element.childNodes;
  var children = [];
  for (var i = 0; i < nodes.length; i++) {
    if (nodes[i].nodeType == Node.ELEMENT_NODE) children.push(nodes[i]);
  }
  return children;
}

getChildren(b).length;