warn_plus_overloading

i have my php.ini with
log_errors = on
error_log = phperror.log
warn_plus_overloading = on

running PHP4.2.2 on Apache 2.0.39 on Win2k with

<?php
echo 'ab' + 'cd';
?>

produces a 0 (zero) and no warnings in phperror.log


(now that i'm writing this i thought of trying displaying the errors to the output -- will be back in a bit)

how come?
don't warnings get logged?
do i have something misconfigured?

any help appreciated

no display of this warning to the screen

yes, it produces no warnings as it is a perfectly valid piece of code (it takes any letters as a 0). What its doing is the math: 0 + 0 = 0.

What i think you are trying to do is produce abcd on the output - to do this you need to use '.' not '+' as follows:

i know it is valid; i thought PHP would say something to avoid nasty errors

http://www.php.net/manual/en/configuration.php#ini.warn-plus-overloading

imagine this:

<?php
$class = 't';
$type = 3;
echo $class . $type; // ok: 't3'
// now imagine i forgot the dot
// and concatenate with '+'
echo $a + $b; // ok: 3 ???
// further imagine this:
$q = 'select * from table where field='' . ($a + $b) . ''';
// and we've got a nasty bug
?>