C read xmlvalidatingreader xml system
We can see clearly that there is a catalogue containing CDs, each of which contains some tracks (music aficionados will notice that I have cut down the track listings for space! You can also see that XML can be less efficient than some other file formats.
Yet, in many cases, the loss in efficiency that results from the increased size can be made up by the speed of processing a well-defined XML file, as parsers (programs that read XML) can predict the structure.
The "area code" for XML namespaces is a URI, which is associated with a prefix for the namespace.
We define a namespace using an xmlns declaration, followed by the prefix, which is equal to a URI that uniquely identifies the namespace: Parsers can now recognise both meanings of "film type" and handle them accordingly.
When we add an area code and, perhaps, an international code, we make the number unique: 44 020 545-321.For example, take the following XML files, both of which describe some data: The first file specifies genres of movies, while the second specifies different types of camera film.But, as the consumers of these files, how can we differentiate between them? An XML namespace allows us to qualify an element in the same way as telephone area codes qualify phone numbers.To start using XML effectively, a sound knowledge of its terminology and file structures needs to be gained.to the end of the opening tag, as with the track element above.