Backward Incompatible Changes

Date

DateTime::createFromImmutable() now has a tentative return type of static, previously it was DateTime.

DateTimeImmutable::createFromMutable() now has a tentative return type of static, previously it was DateTimeImmutable.

number symbols in relative formats no longer accept multiple signs, e.g. +-2.

ODBC

The ODBC extension now escapes the username and password for the case when both a connection string and username/password are passed, and the string must be appended to. Before, user values containing values needing escaping could have created a malformed connection string, or injected values from user-provided data. The escaping rules should be identical to the .NET BCL DbConnectionOptions behaviour.

PDO_ODBC

The PDO_ODBC extension also escapes the username and password when a connection string is passed. See the change to the ODBC extension for further details.

Standard

glob() now returns an empty array if all paths are restricted by open_basedir. Previously it returned false. Moreover, a warning is now emitted even if only some paths are restricted by open_basedir.

FilesystemIterator::__construct(): prior to PHP 8.2.0, FilesystemIterator::SKIP_DOTS constant was always set and couldn't be disabled. In order to maintain the previous behaviour the constant must be explicitly set when using the flags parameter. The default value from flags parameter has not been modified.

strtolower(), strtoupper(), stristr(), stripos(), strripos(), lcfirst(), ucfirst(), ucwords(), and str_ireplace() are no longer locale-sensitive. They now perform ASCII case conversion, as if the locale were "C". Localized versions of these functions are available in the MBString extension. Moreover, array_change_key_case(), and sorting with SORT_FLAG_CASE now also use ASCII case conversion.

str_split() returns an empty array for an empty string now. Previously it returned an array with a single empty string entry. mb_str_split() is not affected by this change as it was already behaving like that.

ksort() and krsort() now do numeric string comparison under SORT_REGULAR using the standard PHP 8 rules now.

var_export() no longer omits the leading backslash for exported classes, i.e. these are now fully qualified.

Standard PHP Library (SPL)

The following methods now enforce their signature:

SplFileObject::hasChildren() now has a tentative return type of false, previously it was bool.

SplFileObject::getChildren() now has a tentative return type of null, previously it was ?RecursiveIterator.

GlobIterator now returns an empty array if all paths are restricted by open_basedir. Previously it returned false. Moreover, a warning is now emitted even if only some paths are restricted by open_basedir.