Placing xmlns="http://www.ksharma.in/myXSD"
on the root element of your XML puts the root and its descendants in the http://www.ksharma.in/myXSD
namespace. This effectively means that all of the element names in your XML document are preceded by http://www.ksharma.in/myXSD
. Yet, the elements stated in your XPath are not in the http://www.ksharma.in/myXSD
namespace. Thus, your XPath matches nothing.
Placing xmlns:conf="http://www.ksharma.in/myXSD"
instead on the root element merely defines a prefix for the http://www.ksharma.in/myXSD
namespace but doesn't actually use it. The root element and its descendants remain in no namespace and are therefore able to be found by your XPath that also tests in no namespace. Thus, your XPath matches something.