PHP 3.0 is rewritten from the ground up. It has a
proper parser that is much more robust and consistent than
2.0's. 3.0 is also significantly faster, and uses less
memory. However, some of these improvements have not been
possible without compatibility changes, both in syntax and
functionality.
In addition, PHP's developers have tried to clean up
both PHP's syntax and semantics in version 3.0, and this
has also caused some incompatibilities. In the long run, we
believe that these changes are for the better.
This chapter will try to guide you through the
incompatibilities you might run into when going from PHP/FI
2.0 to PHP 3.0 and help you resolve them. New features are
not mentioned here unless necessary.
A conversion program that can automatically convert
your old PHP/FI 2.0 scripts exists. It can be found in the
convertor subdirectory of the PHP
3.0 distribution. This program only catches the syntax
changes though, so you should read this chapter carefully
anyway.