Hi Huqui, On Fri, Apr 1, 2016 at 1:47 AM, Huqiu Liao <liaohu...@gmail.com> wrote: > 4 echo (++$i) + (++$i);
I brought up this topic before and the conclusion is This kind of operation result is undefined and user shouldn't write such expression. There are undefined behaviors for ++ and --. C/C++ has undefined behavior for ++/-- https://en.wikipedia.org/wiki/Undefined_behavior#Examples_in_C_and_C.2B.2B Some languages do not have these operators for this reason. PHP may define behavior for these, but it is undefined for future improvements. (And behavior is changed in PHP 7.0) Regards, -- Yasuo Ohgaki yohg...@ohgaki.net -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
