# RFC: Deprecations for PHP 8.7 - Status: Draft - Authors: Daniel Scherzer daniel.e.scherzer@gmail.com - Date: 2026-08-12 - Original: https://wiki.php.net/rfc/deprecations_php_8_7 - Page: https://externals.io/rfc/deprecations_php_8_7 - More for agents: search with https://externals.io/search.md?q={query} · RFCs at https://externals.io/rfc.md · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt ## Discussions on the mailing list - [Deprecate b-prefix for strings](https://externals.io/message/132634.md) — started on 2026-09-25, 7 messages --- ## Introduction The RFC proposes to deprecate the listed functionality in PHP 8.7 and remove it in PHP 9 (except where otherwise noted). The following list provides a short overview of the functionality targeted for deprecation, while more detailed explanation is provided in the Proposal section: - Deprecate `is_a` with $object\_or\_class not being a string or object - Deprecate `is_subclass_of` with $object\_or\_class not being a string or object - Deprecate the b prefix for binary strings ## Proposals Each feature proposed for deprecation is voted separately and requires a 2/3 majority. All votes refer to deprecation in PHP 8.7 and removal in PHP 9 (except where otherwise noted). ### Example Deprecation - Author: Name Description ### Deprecate is\_a() with $object\_or\_class not being a string or object - Author: Daniel Scherzer `is_a` is used to check if an object or class name is an instance of some other named class/interface. The first parameter can be either an object to check, or the name of a class. It can also be something other than a string or object, in which case the function will always return false. I.e. code like `is_a(5, "int")` or `is_a(true, "bool")` will always return false. Given that `is_a` always returns false when the first parameter is something other than a string or object, we propose to deprecate providing non-string non-object parameters. If the type of a parameter is not known, the `is_a` call can be preceded with a call to `is_object`. If accepted, calling `is_a` with non-string non-object parameters will emit a deprecation similar to the following: > Deprecated: Calling is\_a() with $object\_or\_class of type %s is deprecated. ### Deprecate is\_subclass\_of() with $object\_or\_class not being a string or object - Author: Daniel Scherzer `is_subclass_of` is used to check if an object or class name is an instance of a subclass of some other named class, or an instance of an interface. It works similarly to `is_a`, except when an object's class is the exact same as the class to check. Like `is_a`, the first parameter can be either an object to check, or the name of a class. It can also be something other than a string or object, in which case the function will always return false. I.e. code like `is_subclass_of(5, "int")` or `is_subclass_of(true, "bool")` will always return false. Given that `is_subclass_of` always returns false when the first parameter is something other than a string or object, we propose to deprecate providing non-string non-object parameters. If the type of a parameter is not known, the `is_subclass_of` call can be preceded with a call to `is_object`. Unlike `is_a`, `is_subclass_of` also semantically makes no sense for non objects (or string class names) because there is no subclassing concept for non-objects. If accepted, calling `is_subclass_of` with non-string non-object parameters will emit a deprecation similar to the following: > Deprecated: Calling is\_subclass\_of() with $object\_or\_class of type %s is deprecated. ### Deprecate the b prefix for binary strings - Author: Daniel Scherzer - Juliette Reinders Folmer [php-internals\_nospam@adviesenzo.nl](mailto:php-internals_nospam@adviesenzo.nl) TODO