It contains many new features, such as explicit typing of class constants, deep-cloning of readonly properties and additions to the randomness functionality. As always it also includes performance improvements, bug fixes, and general cleanup.
json_validate functiongc_status() returns additional GC informationRandom extension: New \Random\Randomizer::getBytesFromString methodRandom extension: New \Random\Randomizer::getFloat() and nextFloat() methodsphp -l) supports linting multiple files at onceclass_alias() supports aliasing built-in PHP classesstream_context_set_options functionunserialize(): Upgrade E_NOTICE errors to E_WARNINGhighlight_file and highlight_string output HTML changesDateTime Exceptions$_SERVER['SERVER_SOFTWARE'] value changed for RFC3875 complianceget_class() and get_parent_class() function calls without arguments deprecated