#20644 [Opn]: Incrementing/Decrementing booleans != boolean+1

ID: 20644 Updated by: philip@php.net -Summary: in some cases ++ operation DOESN'T work Reported By: yury@krasu.ru Status: Open -Bug Type: Documentation problem +Bug Type: Scripting Engine problem -Operating System: Win32, FreeBSD +Operating System: all -PHP Version: 4.2.1 +PHP Version: 4.3.0-dev New Comment: Please explain how this is to be documented (why this isn't a bug) as I fail to understand the seemingly inconsistent behavior of this example: $t = true; $a = $t + 1; (same as $t += 1; // 2) $b = ++$t; print "a: $a b: $b"; // a: 2 b: 1 In otherwords, incrementing/decrementing a boolean keeps it as boolean while adding an integer, such as 1, changes it to an integer. Reclassifying as a scripting engine problem so php-dev gets this report. Please provide a documentable reason for this behavior. Previous Comments: ------------------------------------------------------------------------ [2002-11-27 01:49:34] sniper@php.net Reclassified. ------------------------------------------------------------------------ [2002-11-27 01:24:49] yury@krasu.ru it was really an user error, sorry. i found than "++" operator doesn't make type conversion from boolean to int, and if variable is boolean and equals TRUE than after ++ it remains as TRUE, so $a = TRUE; echo ($a++).$a; produces output "11" this behavior of increment operator was unexpected to me and i suppose that it can be the same to others, so i wrote an user note at "type juggling" part at online documentation ------------------------------------------------------------------------ [2002-11-26 20:37:54] sniper@php.net Not known and most likely user error. Please provide a reproducing script. ------------------------------------------------------------------------ [2002-11-26 07:32:11] yury@krasu.ru After installing PHP 4.2.1 in some time I noticed a strange bug: at some situation increment operation (++) didn't work! I failed to write a simple code to reproduce that bug (it occurs regular at the same situation in nested functions of a rather big project), but in short - when trying to increment by ++ operation a function parameter, which was setted to 1 as a default parameter value of upper function (which called that function), incrementation does NOT happen. and such code as echo $newteamid; $newteamid++; echo $newteamid; $a = $newteamid; echo $a; $a++; echo $a; produces an output: "1111" but if I use " += 1" instead of "++" all works ok (and I was to make so at my project) as I mentioned I tried to reproduce that bug at simple code, but it works ok in a short program with the same variables values. and the same occurs at PHP 4.2.3. if that bug is not known I can try to write an example for this (dont wanna waste a time if it's well-known) but please confirm that ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=20644&edit=1