<Tr> <Td> 5.4 </Td> <Td> 1 March 2012 </Td> <Td> 3 September 2015 </Td> <Td> Trait support, short array syntax support . Removed items: register_globals, safe_mode, allow_call_time_pass_reference, session_register (), session_unregister () and session_is_registered (). Built - in web server . Several improvements to existing features, performance and reduced memory requirements . </Td> </Tr> <Tr> <Td> 5.5 </Td> <Td> 20 June 2013 </Td> <Td> 10 July 2016 </Td> <Td> Support for generators, finally blocks for exceptions handling, OpCache (based on Zend Optimizer+) bundled in official distribution . </Td> </Tr> <Tr> <Td> 5.6 </Td> <Td> 28 August 2014 </Td> <Td> 31 December 2018 </Td> <Td> Constant scalar expressions, variadic functions, argument unpacking, new exponentiation operator, extensions of the use statement for functions and constants, new phpdbg debugger as a SAPI module, and other smaller improvements . </Td> </Tr> <Tr> <Td> 6. x </Td> <Td> Not released </Td> <Td> N / A </Td> <Td> Abandoned version of PHP that planned to include native Unicode support . </Td> </Tr>

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