Backward Incompatible Changes
PHP Core
$GLOBALS Access Restrictions
Access to the $GLOBALS array is now subject to
a number of restrictions.
Read and write access to individual array elements like
$GLOBALS['var'] continues to work as-is.
Read-only access to the entire $GLOBALS array also
continues to be supported.
However, write access to the entire $GLOBALS array
is no longer supported. For example, array_pop($GLOBALS)
will result in an error.
Usage of static Variables in Inherited Methods
When a method using static variables is inherited (but not overridden), the inherited method will now share static variables with the parent method.
<?php
class A {
public static function counter() {
static $counter = 0;
$counter++;
return $counter;
}
}
class B extends A {}
var_dump(A::counter()); // int(1)
var_dump(A::counter()); // int(2)
var_dump(B::counter()); // int(3), previously int(1)
var_dump(B::counter()); // int(4), previously int(2)
?>
Optional parameters specified before required parameters
An optional parameter specified before required parameters is now always treated as required, even when called using named arguments. As of PHP 8.0.0, but prior to PHP 8.1.0, the below emits a deprecation notice on the definition, but runs successfully when called. As of PHP 8.1.0, an error of class ArgumentCountError is thrown, as it would be when called with positional arguments.
<?php
function makeyogurt($container = "bowl", $flavour)
{
return "Making a $container of $flavour yogurt.\n";
}
try
{
echo makeyogurt(flavour: "raspberry");
}
catch (Error $e)
{
echo get_class($e), ' - ', $e->getMessage(), "\n";
}
?>
Output of the above example in PHP 8.0:
Deprecated: Required parameter $flavour follows optional parameter $container in example.php on line 3 Making a bowl of raspberry yogurt.
Output of the above example in PHP 8.1:
Deprecated: Optional parameter $container declared before required parameter $flavour is implicitly treated as a required parameter in example.php on line 3 ArgumentCountError - makeyogurt(): Argument #1 ($container) not passed
Note that a default value of null can be used before required parameters to
specify a nullable type,
but the parameter will still be required.
Return Type Compatibility with Internal Classes
Most non-final internal methods now require overriding methods to declare
a compatible return type, otherwise a deprecated notice is emitted during
inheritance validation.
In case the return type cannot be declared for an overriding method due to
PHP cross-version compatibility concerns,
a #[ReturnTypeWillChange] attribute can be added to silence
the deprecation notice.
New Keywords
readonly is a keyword now. However, it still may be used
as function name.
never is now a reserved word, so it cannot be used to name a class,
interface or trait, and is also prohibited from being used in namespaces.
Resource to Object Migration
Several resources have been migrated to objects.
Return value checks using is_resource() should be replaced with checks for false.
-
The FileInfo functions now accept and return finfo objects instead of
fileinforesources. -
The FTP functions now accept and return FTP\Connection objects instead of
ftpresources. -
The IMAP functions now accept and return IMAP\Connection objects instead of
imapresources. -
The LDAP functions now accept and return LDAP\Connection objects instead of
ldap linkresources. -
The LDAP functions now accept and return LDAP\Result objects instead of
ldap resultresources. -
The LDAP functions now accept and return LDAP\ResultEntry objects instead of
ldap result entryresources. -
The PgSQL functions now accept and return PgSql\Connection objects instead of
pgsql linkresources. -
The PgSQL functions now accept and return PgSql\Result objects instead of
pgsql resultresources. -
The PgSQL functions now accept and return PgSql\Lob objects instead of
pgsql large objectresources. -
The PSpell functions now accept and return PSpell\Dictionary objects instead of
pspellresources. -
The PSpell functions now accept and return PSpell\Config objects instead of
pspell configresources.
MySQLi
mysqli_fetch_fields(), and
mysqli_fetch_field_direct() will now always return
0 for the max_length.
This information can be computed by iterating over the result set,
and taking the maximum length. This is what PHP was doing
internally previously.
The MYSQLI_STMT_ATTR_UPDATE_MAX_LENGTH
option no longer has any effect.
The MYSQLI_STORE_RESULT_COPY_DATA
option no longer has any effect. Passing any value to the
mode parameter of
mysqli::store_result() no longer has any effect.
mysqli::connect() now returns true instead of null on success.
The default error handling mode has been changed from "silent" to "exceptions"
See the MySQLi reporting mode
page for more details on what this entails,
and how to explicitly set this attribute.
To restore the previous behaviour use:
mysqli_report(MYSQLI_REPORT_OFF);
Classes extending mysqli_stmt::execute() are now required to specify the additional optional parameter.
MySQLnd
The mysqlnd.fetch_data_copy INI directive has been removed. This should not result in user-visible behavior changes.
OpenSSL
EC private keys will now be exported in PKCS#8 format rather than traditional format, just like all other keys.
openssl_pkcs7_encrypt() and openssl_cms_encrypt() will now to default using AES-128-CBC rather than RC2-40. The RC2-40 cipher is considered insecure and not enabled by default by OpenSSL 3.
PHP Data Objects
PDO::ATTR_STRINGIFY_FETCHES now stringifies values
of type bool to "0" or
"1". Previously bools were not stringified.
Calling PDOStatement::bindColumn() with
PDO::PARAM_LOB will now constantly bind a stream
result when PDO::ATTR_STRINGIFY_FETCHES is not enabled.
Previously, the result would either be a stream or a string depending on
the used database driver and the time the binding is performed.
MySQL Driver
Integers and floats in result sets will now be returned using native
PHP types instead of strings when using emulated prepared statements.
This matches the behavior of native prepared statements.
The previous behaviour can be restored by enabling the
PDO::ATTR_STRINGIFY_FETCHES option.
SQLite Driver
Integers and floats in results sets will now be returned using native
PHP types.
The previous behaviour can be restored by enabling the
PDO::ATTR_STRINGIFY_FETCHES option.
Phar
To comply with the ArrayAccess interface, Phar::offsetUnset() and PharData::offsetUnset() no longer return a bool.
Standard
version_compare() no longer accepts undocumented operator abbreviations.
htmlspecialchars(),
htmlentities(),
htmlspecialchars_decode(),
html_entity_decode(),
and get_html_translation_table()
now use ENT_QUOTES | ENT_SUBSTITUTE rather than
ENT_COMPAT by default.
This means that ' is escaped to
' while previously nothing was done.
Additionally, malformed UTF-8 will be replaced by a Unicode substitution
character, instead of resulting in an empty string.
debug_zval_dump() now prints the refcount of a reference
wrappers with their refcount, instead of only prepending
& to the value.
This more accurately models reference representation since PHP 7.0.
debug_zval_dump() now prints interned
instead of a dummy refcount for interned strings and immutable arrays.
Standard PHP Library (SPL)
SplFixedArray, will now be JSON encoded like an array
