Bug #69558 [Nab]: switch statement output unexpected

Edit report at https://bugs.php.net/bug.php?id=69558&edit=1 ID: 69558 User updated by: stephane at winnepenninckx dot com Reported by: stephane at winnepenninckx dot com Summary: switch statement output unexpected Status: Not a bug Type: Bug Package: Scripting Engine problem Operating System: mac os x 10.10 PHP Version: 5.6.8 Block user comment: N Private report: N New Comment: I would like that you are right. But I rewrote the switch with 'else if' the way you pretend the switch statement is working and I ended with a different result. for ($i = 10; $i >= 0; --$i){ if ($i == ($i < 1)){ $msg = 'really'; }else if ($i == ($i < 3)) { $msg = 'quite bad'; }else if ($i == ($i < 5)) { $msg = 'pay attention'; }else if ($i == ($i <= 9)){ $msg = 'quite good'; }else if ($i == ($i <= 10)){ $msg = 'congrat'; }else{ $msg == 'Oops'; } echo $i.' '.$msg . $sep; } for $i with value '04 it returns: '0 quite bad' where the switch statement returns '0 : Oops' IMHO this is different. Previous Comments: ------------------------------------------------------------------------ [2015-05-01 18:10:37] requinix@php.net If they think it's a bug then they must not have as much experience with PHP as they claim. "switch (X) case Y:" is equivalent to "if (X == Y)", so what you've written is like if ($i == ($i < 1)) { } else if ($i == ($i < 3)) { } etc Obviously that's not what you wanted. A switch doesn't make sense for that. It's most useful for dealing with specific values, like if you wanted different behavior for specific values of $i, and not for general conditional logic. Use if instead. ------------------------------------------------------------------------ [2015-05-01 17:57:59] stephane at winnepenninckx dot com I've asked around and people with lot of experience in PHP asked me to file a bug, because they believe it is one. It 's too easy to say it is not bug. ------------------------------------------------------------------------ [2015-05-01 16:24:08] nikic@php.net Sorry, but your problem does not imply a bug in PHP itself. For a list of more appropriate places to ask for help using PHP, please visit http://www.php.net/support.php as this bug system is not the appropriate forum for asking support questions. Due to the volume of reports we can not explain in detail here why your report is not a bug. The support channels will be able to provide an explanation for you. Thank you for your interest in PHP. ------------------------------------------------------------------------ [2015-05-01 15:37:58] stephane at winnepenninckx dot com Description: ------------ the case $i < 1 down not occur for $i = 0, the script goes to the default case: ----------------- 0 : Oops ----------------- If you delete the default case : ----------------- 0 : quite bad! ----------------- I try with the for loop modified : for ($i = 10.1; $i >= 0; --$i) then the case $i<1 occurs : ----------------- 0.1 : really!! ----------------- It looks like there is a problem with the value 0 when comparing to 1 also in older versions of PHP like 5.5 Test script: --------------- $sep = PHP_EOL.'-----------------'.PHP_EOL; echo 'switch demo'; echo $sep; for ($i = 10; $i >= 0; --$i) { switch($i) { case $i < 1 : $msg = 'really!!'; break; case $i < 3 : $msg = 'quite bad!'; break; case $i < 5 : $msg = 'pay attention!'; break; case $i <= 9 : $msg = 'quite good'; break; case $i <= 10 : $msg = 'congrat'; break; default: $msg = 'Oops'; break; } echo $i . ' : '.$msg.$sep; } Expected result: ---------------- when $i = 0 the $msg should be 'really!!' not 'Oops': ----------------- 0 : really!! ----------------- ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=69558&edit=1