Detailed explanation of reading and writing XML and DOM in PHP_PHP Tutorial

Reading and writing Extensible Markup Language (XML) in PHP can seem a little scary. In fact, XML and all its related technologies can be scary, but reading and writing XML in PHP doesn't have to be a scary task. First, you need to learn a little about XML: what it is and what to do with it. Then, you need to learn how to read and write XML in PHP, and there are many ways to do this.

What is XML?
XML is a data storage format. It does not define what data is saved, nor does it define the format of the data. XML just defines tags and the attributes of those tags. A well-formed XML tag looks like this:
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This tag contains some text: Jack Herrington. An XML tag that doesn't contain text looks like this:


There's more than one way to write something in XML. For example, this tag forms the same output as the previous tag:


You can also add attributes to XML tags. For example, this tag contains first and last attributes:


Special characters can also be encoded in XML. For example, the & symbol can be encoded like this:
&

An XML file containing tags and attributes is well-formed if it is formatted like the example, meaning that the tags are symmetrical and the characters are encoded correctly . Listing 1 is an example of well-formed XML.

Listing 1. XML book list example


Jack Herrington /title>
OReilly


Jack Herrington Podcasting Hacks
OReilly



The XML in Listing 1 contains a list of books. The parent tag contains a set of tags, each of which contains ,