PHP 8.6, scheduled for release on November 19, 2026, introduces several notable features: partial function application (PFA) for prefilling closure parameters, readonly property defaults (now allowed when implementing interfaces with property hooks), a new low-level Polling API for I/O multiplexing with epoll/WSAPoll backends, a built-in clamp() function, new isReadable/isWriteable reflection methods, function parameter doc comments via ReflectionParameter::getDocComment(), a SortDirection enum, debuggable enums via __debugInfo(), and improved session security defaults (HttpOnly, SameSite=Lax). The release also includes a large set of deprecations covering legacy functions (is_double, is_integer, is_long, doubleval, strcoll, metaphone, spl_classes, spl_object_hash), ArrayIterator methods, SplFileObject CSV methods, returning from finally blocks and constructors/destructors, and reserving keywords like let, is, and namespace for future syntax.
Table of contents
Partial function applicationReadonly property defaultsPolling APIA new clamp functionNew isReadable and isWriteable reflection functionsFunction parameter doc commentsA new SortDirection enumImproved security for session defaultsDebugable enumsDeprecations597.9K Impressions7 Comments