PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

6 Introduction
Source Code
You have access to PHP’s source code.With PHP, unlike commercial, closed-source
products, if you want to modify something or add to the language, you are free to do so.
You do not need to wait for the manufacturer to release patches.You also don’t need
to worry about the manufacturer going out of business or deciding to stop supporting a
product.
Availability of Support and Documentation
Zend Technologies (www.zend.com), the company behind the engine that powers PHP,
funds its PHP development by offering support and related software on a commercial
basis.
The PHP documentation and community are mature and rich resources with a
wealth of information to share.
What Is New in PHP 5?
You may have recently moved to PHP 5 from one of the PHP 4.x versions. As you
would expect in a new major version, it has some significant changes.The Zend engine
beneath PHP has been rewritten for this version. Major new features are as follows:
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Better object-oriented support built around a completely new object model (see
Chapter 6,“Object-Oriented PHP”)
Exceptions for scalable, maintainable error handling (see Chapter 7,“Error and
Exception Handling”)
SimpleXML for easy handling of XML data (see Chapter 33,“Connecting to Web
Services with XML and SOAP”)
Other changes include moving some extensions out of the default PHP install and into
the PECL library, improving streams support, and adding SQLite.
At the time of writing, PHP 5.2 was the current version, with PHP 5.3 on the near
horizon. PHP 5.2 added a number of useful features including:
n The new input filtering extension for security purposes
n JSON extension for better JavaScript interoperability
n File upload progress tracking
n Better date and time handling
n Many upgraded client libraries, performance improvements (including better
memory management in the Zend Engine), and bug fixes
Key Features of PHP 5.3
You may have heard about a new major release of PHP, called PHP 6. At the time of
this writing, PHP 6 is not in the release candidate stage, and hosting providers won’t be