ID:               42152
 User updated by:  php at tfwasmus dot enschedenet dot nl
 Reported By:      php at tfwasmus dot enschedenet dot nl
-Status:           Feedback
+Status:           Closed
 Bug Type:         Scripting Engine problem
 Operating System: Windows Xp x64
 PHP Version:      5CVS-2007-07-30 (snap)
 New Comment:

Hmm, after some consultation & a good night sleep I agree it's not a
bug in operator precedence. It's more an undefined state of the operand
which is the problem. 

Indeed: undefined behaviour, so the difference between PHP4 & PHP5
should not matter: a statement like this just shouldn't be used/relied
upon.

The fact it's behaviour has changed between versions is however IMO
enough reason to keep this in the bug database for people to find.


Previous Comments:
------------------------------------------------------------------------

[2007-07-31 13:23:32] smlerman at gmail dot com

Last I knew, using a variable that you post-increment (and maybe
pre-increment, can't remember for sure) elsewhere in the same statement
results in undefined behavior.

------------------------------------------------------------------------

[2007-07-31 11:33:46] [EMAIL PROTECTED]

Either I missed something but = has lower precedence than [ ?


------------------------------------------------------------------------

[2007-07-30 23:26:44] php at tfwasmus dot enschedenet dot nl

Description:
------------
According to the operator precedence
(http://www.php.net/manual/en/language.operators.php#language.operators.precedence),
a (post)increment should be evalued after the '['.

It seems that isn't true in assigning to an array in PHP5 anymore,
while it was in PHP4. Latest snapshots of both checked (30-07-2007).

This could also be a documentation problem.

Reproduce code:
---------------
<?php
$k = 1;
$a = array();
$a[$k] = $k++;
var_dump($a,$k);
?>

Expected result:
----------------
array(1) {
  [1]=>
  int(1)
}
int(2)

Actual result:
--------------
array(1) {
  [2]=>
  int(1)
}
int(2)


------------------------------------------------------------------------


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