#34772 [Bgs]: Weird type juggling problem (may not be a bug at all)

ID: 34772 User updated by: rn214 at cam dot ac dot uk Reported By: rn214 at cam dot ac dot uk Status: Bogus Bug Type: *General Issues Operating System: Linux PHP Version: 4.4.0 New Comment: Sorry to trouble you. The behaviour does seem wrong to me, so I thought it was better to report it as a possible bug than to ignore it. Previous Comments: ------------------------------------------------------------------------ [2005-10-07 09:36:37] sniper@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. Try var_dump() on it.. ------------------------------------------------------------------------ [2005-10-07 06:37:17] rn214 at cam dot ac dot uk Description: ------------ Something rather weird happens when you define a variable first as a string and then as an array. I am not sure whether this is actually a bug, or my failure to understand null-terminated strings. However, the effect is that the empty-string '' is evaluated as true. Sorry for wasting your time if this is spurious. Reproduce code: --------------- $foo[1]="x"; $foo=$foo[1]; $foo[2]=''; if ($foo[1]){ echo "foo 1 is '$foo[1]' and is true<br>"; } if ($foo[2]){ #The value of $foo[2] printed here is \0. It evalutes as true, and is a 1-character length string. #This is DESPITE that fact that I just set it to be empty! echo "foo 2 is '$foo[2]' and is true<br>"; } #A simpler case: $bar="x"; $bar[2]=''; echo "bar 2 is '$bar[2]'<br>"; Expected result: ---------------- Not quite sure what to expect. But I do not expect the value of foo[2] which I just set to the empty string to evaluate as true! I would expect only to see one line: bar is '' Actual result: -------------- foo 1 is ' ' and is true foo 2 is 'N' and is true bar is 'N' (I have used the character N to represent NUL, since it would otherwise be invisible. Also note the space between the quotes in the first line) ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=34772&edit=1