PHP is a scripting language for creating dynamic websites based on the server. You can use PHP and HTML to generate the website homepage. When a visitor opens the homepage, the server executes the PHP command and sends the execution results to the visitor's browser, similar to ASP and CoildFusion.
However, the difference between PHP and them is that PHP is open source and cross-platform. PHP can run on WINDOWS NT and multiple versions of UNIX. It doesn't require any pre-processing for fast feedback, and it doesn't require mod_perl tweaks to make your server's memory image smaller.
PHP consumes fewer resources. When PHP is used as part of the Apache web server, there is no need to call external binaries to run the code, and the server does not need to bear any additional burden.
In addition to being able to manipulate your pages, PHP can also send headers for HIIP. You can set cookies, manage digital signatures and redirect users, and it provides excellent connectivity to other databases (also DBC), integrating various external libraries to do anything from parsing XML with PDF documents.
PHP programming language is similar to C and Perl. You don't have to declare any variables before using them, and creating arrays and hashes is a simple matter. PHP also has some object-oriented features that can provide great help in organizing and packaging your code.
PHP version 5 introduces SimpleXML, a new application programming interface (API) for reading and writing XML. It enables PHP pages to query, search, modify and republish XML in PHP-friendly syntax.
SimpleXML is a great new addition to the PHP programmer's toolbox. There are many applicable situations. Specifically, it works well with simple, record-like data that is much simpler than using the DOM. You can try SimpleXML yourself. It should be able to become a reliable and robust XML processing method in PHP.
Next, let's assume that a PHP page is needed to convert an RSS feed into HTML. We start using SimpleXML to complete it. How to start? Let's see!
http://blog.csdn.net/ibmjournal/archive/2006/10/31/1358791.aspx