This faq section will help you migrate from PHP 4 to PHP 5.
Migrating from PHP 4 to PHP 5
Although PHP 5 offers many new features, it's designed to be as compatible with earlier versions of PHP as possible with little functionality being broken in the process.
Be sure to read the appropriate PHP 5 migration appendix of this manual as it contains even more information on the topic of migrating to PHP 5.
Does MySQL work in PHP 5? It seemed to have disappeared.
MySQL is supported with the only
change being that MySQL support is no longer enabled by
default in PHP 5. This essentially means that
PHP doesn't include the
Also, the MySQL client libraries are no longer bundled with PHP. More
details on this topic are covered in
the following FAQ and
be sure to read the MySQL section
for details on installing MySQL. An example configure line would be
I hear PHP 5 has an entirely new OOP model, will my existing OOP code work? Where do I find information on these new OOP features?
The main change in PHP 5 is to the OOP model as PHP 5 now uses the Zend Engine 2.0. The zend.ze1_compatibility_mode directive enables compatability with the Zend Engine 1.0 (PHP 4).
So besides the new OOP model, what else has changed in PHP 5? Also, is there a PHP 5 specific version of the PHP manual?
Few other changes exist, see the migration 5 appendix for details. There won't be a PHP 5 specific version of the manual as the bulk of PHP remains the same.