It's just basic polymorphism. An Element "IS A" Node, because Element is a subinterface of Node. That means that Element has all the methods that Node does. It also means that Element could have some other methods that Node doesn't have, and in fact it does. It has methods allowing you to access the attributes of the element. Those methods aren't in the Node interface because not all types of nodes have attributes.
Joined: May 28, 2008
thanks..so meaning now it find i declare as Element and send as and Node type..thanks..no i start to like programming....