How to find out if an XML document contains a certain element (by tag name)?

Question

Suppose I have downloaded a valid XML document via Ajax (var docum = request.responseXML;). Now how do I find out if it contains a certain element (by tag name)?

Answer 1

You can use the getElementsByTagName method, e.g.

var scripts = docum.getElementsByTagName('script');
if (scripts.length > 0) {
  // contains.
}

Answer 2

if(xml.getElementsByTagName("myTag").length > 0){
    alert("myTag is here");
}else{
    alert("myTag is NOT here")
}