Backward incompatible changes

Changes to Foreach

Minor changes have been made to the behaviour of the Foreach control structure, primarily...

Changes to error and exception handling

Many fatal and recoverable fatal errors have been converted to exceptions in PHP 7. These...

Changes to int handling

Previously, octal literals that contained invalid numbers were silently truncated (0128 wa...

Changes to string handling

Strings containing hexadecimal numbers are no longer considered to be numeric. For example...

Changes to variable handling

PHP 7 now uses an abstract syntax tree when parsing source files. This has permitted many...

Other backward incompatible changes

The result of the New statement can no longer be assigned to a variable by reference:

Removed INI directives

The following INI directives have been removed as their associated features have also been...

Removed functions

These functions were deprecated in PHP 4.1.0 in favour of call_user_func and call_user_fun...