Changes in SAPI Modules

CLI

Using -a without the readline extension will now result in an error. Previously, -a without readline had the same behavior as calling php without any arguments, apart from printing an additional "Interactive mode enabled" message. This mode was not interactive.

PHPDBG

Remote functionality from phpdbg has been removed.

Changed Functions

Core

The order of properties used in foreach, var_dump(), serialize(), object comparison, etc. was changed. Properties are now ordered naturally according to their declaration and inheritance. Properties declared in a base class are going to be before the child properties.

This order is consistent with internal layout of properties in zend_object structure and repeats the order in default_properties_table[] and properties_info_table[]. The old order was not documented and was caused by class inheritance implementation details.

Filter

The FILTER_FLAG_ALLOW_OCTAL flag of the FILTER_VALIDATE_INT filter now accept octal string with the leading octal prefix ("0o"/"0O").

GMP

All GMP functions now accept octal string with the leading octal prefix ("0o"/"0O").

PDO ODBC

PDO::getAttribute() with PDO::ATTR_SERVER_INFO and PDO::ATTR_SERVER_VERSION now return values instead of throwing PDOException.

Reflection

ReflectionProperty::setAccessible() and ReflectionMethod::setAccessible() no longer have an effect. Properties and methods are now always considered accessible via Reflection.

Standard

syslog() is now binary safe.

Other Changes to Extensions

GD

imagewebp() can now do lossless WebP encoding by passing IMG_WEBP_LOSSLESS as the quality.

This constant is only defined, if the used libgd supports lossless WebP encoding.

MySQLi

mysqli_stmt::next_result() and mysqli::fetch_all() are now available when linking against libmysqlclient.

OpenSSL

The OpenSSL extension now requires at least OpenSSL version 1.0.2.
OpenSSL 3.0 is now supported. Be aware that many ciphers are no longer enabled by default (part of the legacy provider), and that parameter validation (e.g. minimum key sizes) is stricter now.

Phar

SHA256 is now used by default for signatures.
Added support for OpenSSL_SHA256 and OpenSSL_SHA512 signatures.

SNMP

Added support for SHA256 and SHA512 for the security protocol.

Standard

--with-password-argon2 now uses pkg-config to detect libargon2. As such, an alternative libargon2 location should now be specified using PKG_CONFIG_PATH.

Changes to INI File Handling

The log_errors_max_len INI directive has been removed. It no longer had an effect since PHP 8.0.0.
A leading dollar in a quoted string can now be escaped: "\${" will now be interpreted as a string with contents ${.
Backslashes in double quoted strings are now more consistently treated as escape characters. Previously, "foo\\" followed by something other than a newline was not considered as a terminated string. It is now interpreted as a string with contents foo\. However, as an exception, the string "foo\" followed by a newline will continue to be treated as a valid string with contents foo\ rather than an unterminated string. This exception exists to support naive uses of Windows file paths such as "C:\foo\".