PHP 8.0 UPGRADE NOTES 1. Backward Incompatible Changes 2. New Features 3. Changes in SAPI modules 4. Deprecated Functionality 5. Changed Functions 6. New Functions 7. New Classes and Interfaces 8. Removed Extensions and SAPIs 9. Other Changes to Extensions 10. New Global Constants 11. Changes to INI File Handling 12. Windows Support 13. Other Changes 14. Performance Improvements ======================================== 1. Backward Incompatible Changes ======================================== - Core: . Methods with the same name as the class are no longer interpreted as constructors. The __construct() method should be used instead. . Removed ability to call non-static methods statically. . Removed (unset) cast. . Removed track_errors ini directive. This means that $php_errormsg is no longer available. The error_get_last() function may be used instead. . Removed the ability to define case-insensitive constants. The third argument to define() may no longer be true. . Access to undefined constants now always results in an Error exception. Previously, unqualified constant accesses resulted in a warning and were interpreted as strings. . Removed ability to specify an autoloader using an __autoload() function. spl_autoload_register() should be used instead. . Removed the $errcontext argument for custom error handlers. . Removed create_function(). Anonymous functions may be used instead. . Removed each(). foreach or ArrayIterator should be used instead. . Removed ability to unbind $this from closures that were created from a method, using Closure::fromCallable() or ReflectionMethod::getClosure(). . Any array that has a number n as its first numeric key will use n+1 for its next implicit key. Even if n is negative. RFC: https://wiki.php.net/rfc/negative_array_index . The default error_reporting level is now E_ALL. Previously it excluded E_NOTICE and E_DEPRECATED. . display_startup_errors is now enabled by default. . The @ operator will no longer silence fatal errors (E_ERROR, E_CORE_ERROR, E_COMPILE_ERROR, E_USER_ERROR, E_RECOVERABLE_ERROR, E_PARSE). Error handlers that expect error_reporting to be 0 when @ is used, should be adjusted to use a mask check instead: // Replace function my_error_handler($err_no, $err_msg, $filename, $linenum) { if (error_reporting() == 0) { return; // Silenced } // ... } // With function my_error_handler($err_no, $err_msg, $filename, $linenum) { if (!(error_reporting() & $err_no)) { return; // Silenced } // ... } Additionally, care should be taken that error messages are not displayed in production environments, which can result in information leaks. Please ensure that display_errors=Off is used in conjunction with error logging. . Inheritance errors due to incompatible method signatures (LSP violations) will now always generate a fatal error. Previously a warning was generated in some cases. RFC: https://wiki.php.net/rfc/lsp_errors . The precedence of the concatenation operator has changed relative to bitshifts and addition as well as subtraction. RFC: https://wiki.php.net/rfc/concatenation_precedence . Arguments with a default-value that resolves to null at run-time will no longer implicitly mark the argument type as nullable. Either use an explicit nullable type, or an explicit null default value instead. // Replace function test(int $arg = CONST_RESOLVING_TO_NULL) {} // With function test(?int $arg = CONST_RESOLVING_TO_NULL) {} // Or function test(int $arg = null) {} . A number of warnings have been converted into Error exceptions: * Attempting to write to a property of a non-object. Previously this implicitly created an stdClass object for null, false and empty strings. * Attempting to append an element to an array for which the PHP_INT_MAX key is already used. * Attempting to use an invalid type (array or object) as an array key or string offset. * Attempting to write to an array index of a scalar value. * Attempting to unpack a non-array/Traversable. A number of notices have been converted into warnings: * Attempting to read an undefined variable. * Attempting to read an undefined property. * Attempting to read a property of a non-object. * Attempting to access an array index of a non-array. * Attempting to convert an array to string. * Attempting to use a resource as an array key. * Attempting to use null, a boolean or a float as a string offset. * Attempting to read an out-of-bounds string offset. RFC: https://wiki.php.net/rfc/engine_warnings . Unexpected characters in source files (such as null bytes outside of strings) will now result in a ParseError exception instead of a compile warning. . Uncaught exceptions now go through "clean shutdown", which means that destructors will be called after an uncaught exception. - COM: . Removed the ability to import case-insensitive constants from type libraries. The second argument to com_load_typelib() may no longer be false; com.autoregister_casesensitive may no longer be disabled; case-insensitive markers in com.typelib_file are ignored. - Date: . mktime() and gmmktime() now require at least one argument. time() can be used to get the current timestamp. - dom: . Remove unimplemented classes from ext/dom that had no behavior and contained test data. These classes have also been removed in the latest version of DOM standard: * DOMNameList * DomImplementationList * DOMConfiguration * DomError * DomErrorHandler * DOMImplementationSource * DOMLocator * DOMUserDataHandler * DOMTypeInfo - Exif: . Removed read_exif_data(). exif_read_data() should be used instead. - Filter: . The FILTER_FLAG_SCHEME_REQUIRED and FILTER_FLAG_HOST_REQUIRED flags for the FILTER_VALIDATE_URL filter have been removed. The scheme and host are (and have been) always required. . The INPUT_REQUEST and INPUT_SESSION source for filter_input() etc have been removed. These were never implemented and their use always generated a warning. - GD: . The GD extension now uses objects as the underlying data structure for images, rather than resources. These objects are completely opaque, i.e. they don't have any methods. . The deprecated function image2wbmp() has been removed. RFC: https://wiki.php.net/rfc/image2wbmp . The deprecated functions png2wbmp() and jpeg2wbmp() have been removed. RFC: https://wiki.php.net/rfc/deprecate-png-jpeg-2wbmp . The default $mode parameter of imagecropauto() no longer accepts -1. IMG_CROP_DEFAULT should be used instead. - GMP: . gmp_random() has been removed. One of gmp_random_range() or gmp_random_bits() should be used instead. - Intl: . The deprecated constant INTL_IDNA_VARIANT_2003 has been removed. RFC: https://wiki.php.net/rfc/deprecate-and-remove-intl_idna_variant_2003 . The deprecated Normalizer::NONE constant has been removed. - LDAP: . The deprecated function ldap_sort has been removed. - Mbstring: . The mbstring.func_overload directive has been removed. The related MB_OVERLOAD_MAIL, MB_OVERLOAD_STRING, and MB_OVERLOAD_REGEX constants have also been removed. Finally, the "func_overload" and "func_overload_list" entries in mb_get_info() have been removed. . mb_parse_str() can no longer be used without specifying a result array. . A number of deprecated mbregex aliases have been removed. See the following list for which functions should be used instead: * mbregex_encoding() -> mb_regex_encoding() * mbereg() -> mb_ereg() * mberegi() -> mb_eregi() * mbereg_replace() -> mb_ereg_replace() * mberegi_replace() -> mb_eregi_replace() * mbsplit() -> mb_split() * mbereg_match() -> mb_ereg_match() * mbereg_search() -> mb_ereg_search() * mbereg_search_pos() -> mb_ereg_search_pos() * mbereg_search_regs() -> mb_ereg_search_regs() * mbereg_search_init() -> mb_ereg_search_init() * mbereg_search_getregs() -> mb_ereg_search_getregs() * mbereg_search_getpos() -> mb_ereg_search_getpos() * mbereg_search_setpos() -> mb_ereg_search_setpos() . The 'e' modifier for mb_ereg_replace() has been removed. mb_ereg_replace_callback() should be used instead. . A non-string pattern argument to mb_ereg_replace() will now be interpreted as a string instead of an ASCII codepoint. The previous behavior may be restored with an explicit call to chr(). . The $is_hex parameter, which was not used internally, has been removed from mb_decode_numericentity(). - PCRE: . When passing invalid escape sequences they are no longer intepreted as literals. This behaviour previously required the X modifier - which is now ignored. - PDO: . The method PDOStatement::setFetchMode() now accepts the following signature: PDOStatement::setFetchMode($mode, $classname, $params) - PDO_ODBC: . The php.ini directive pdo_odbc.db2_instance_name has been removed - Reflection: . The method signatures ReflectionClass::newInstance($args) ReflectionFunction::invoke($args) ReflectionMethod::invoke($object, $args) have been changed to: ReflectionClass::newInstance(...$args) ReflectionFunction::invoke(...$args) ReflectionMethod::invoke($object, ...$args) Code that must be compatible with both PHP 7 and PHP 8 can use the following signatures to be compatible with both versions: ReflectionClass::newInstance($arg = null, ...$args) ReflectionFunction::invoke($arg = null, ...$args) ReflectionMethod::invoke($object, $arg = null, ...$args) - Socket: . The deprecated AI_IDN_ALLOW_UNASSIGNED and AI_IDN_USE_STD3_ASCII_RULES flags for socket_addrinfo_lookup() have been removed. - SPL: . SplFileObject::fgetss() has been removed. . SplHeap::compare($a, $b) now specifies a method signature. Inheriting classes implementing this method will now have to use a compatible method signature. - Standard: . assert() will no longer evaluate string arguments, instead they will be treated like any other argument. assert($a == $b) should be used instead of assert('$a == $b'). The assert.quiet_eval ini directive and ASSERT_QUIET_EVAL constants have also been removed, as they would no longer have any effect. . parse_str() can no longer be used without specifying a result array. . fgetss() has been removed. . The string.strip_tags filter has been removed. . The needle argument of strpos(), strrpos(), stripos(), strripos(), strstr(), strchr(), strrchr(), and stristr() will now always be interpreted as a string. Previously non-string needles were interpreted as an ASCII code point. An explicit call to chr() can be used to restore the previous behavior. . The needle argument for strpos(), strrpos(), stripos(), strripos(), strstr() and stristr() can now be empty. . The 'salt' option of password_hash() is no longer supported. If the 'salt' option is used a warning is generated, the provided salt is ignored, and a generated salt is used instead. . The quotemeta() function will now return an empty string if an empty string was passed. Previously false was returned. - tidy: . The $use_include_path parameter, which was not used internally, has been removed from tidy_repair_string(). - XML: . xml_parser_create(_ns) will now return an XmlParser object rather than a resource. Return value checks using is_resource() should be replaced with checks for `false`. The xml_parser_free() function no longer has an effect, instead the XmlParser instance is automatically destroyed if it is no longer referenced. - XMLWriter: . The XMLWriter functions now accept and return, respectively, XMLWriter objects instead of resources. - Zip: . The remove_path option of ZipArchive::addGlob() and ::addPattern() is now treated as arbitrary string prefix (for consistency with the add_path option), whereas formerly it was treated as directory name. This means that if no trailing directory separator is given, the following character is no longer stripped from the filename. - Zlib: . gzgetss() has been removed. ======================================== 2. New Features ======================================== - Core: . Added ValueError class. ======================================== 3. Changes in SAPI modules ======================================== ======================================== 4. Deprecated Functionality ======================================== ======================================== 5. Changed Functions ======================================== ======================================== 6. New Functions ======================================== - Standard: . Added fdiv() method, which performs a floating-point devision under IEEE 754 semantics. Division by zero is considered well-defined and will return one of Inf, -Inf or NaN. ======================================== 7. New Classes and Interfaces ======================================== ======================================== 8. Removed Extensions and SAPIs ======================================== ======================================== 9. Other Changes to Extensions ======================================== ======================================== 10. New Global Constants ======================================== ======================================== 11. Changes to INI File Handling ======================================== ======================================== 12. Windows Support ======================================== ======================================== 13. Other Changes ======================================== ======================================== 14. Performance Improvements ========================================