Appendix B. Migrating from PHP 5.1.x to PHP 5.2.x

Table of Contents
What has changed in PHP 5.2.x
Backward Incompatible Changes
New Error Messages
Changes in PHP datetime support
New Parameters
New Functions
New Methods
Removed Extensions
New Extensions
New Classes
New Global Constants
New Class Constants
New INI Configuration Directives
Error Reporting
Other Enhancements

What has changed in PHP 5.2.x

Most improvements in PHP 5.2.x have no impact on existing code. There are a few incompatibilities and new error messages that should be considered, and code should be tested before switching PHP versions in production environments.

If the system is being upgraded from PHP 5.0.x, the text titled Upgrade Notes for PHP 5.1.x should also be read.

Similarly, if the system is being upgraded from PHP 4, the manual section titled Migrating from PHP 4 to PHP 5 should be read as well.