An XML Document

An XML document has the following general structure but some parts are optional:

• A prolog, which may optionally be empty

• At least one element, the document element, although a typical XML document has a nested structure of elements

• Optional content following the end tag of the document element

Each of these permitted parts of an XML document is described in the remaining sections of this chapter.

A minimal XML document can consist of a single document element, such as this:

<someElementTypeName>The content</someElementTypeName> 

Typically, XML documents are much more complex and have a nested structure of elements. An XML document that uses more of the allowed structures might look like this:

<?xml version="1.0" ?> 
<!-- This is an example XML document. --> 
<!DOCTYPE book > 
<book> 
<title>Sams Teach Yourself XML in 10 Minutes</title> 
<author>Andrew Watt</author> 
</book> 

First let’s look at what can go in the prolog.