Edit report at https://bugs.php.net/bug.php?id=63861&edit=1
ID: 63861
Updated by: ni...@php.net
Reported by: rstoll at tutteli dot ch
Summary: weak logic operator are buggy
-Status: Open
+Status: Not a bug
Type: Bug
Package: Scripting Engine problem
PHP Version: 5.4.10
Block user comment: N
Private report: N
New Comment:
The OR, XOR, AND operators are special variants of the usual logic operator
with different precedence. In particular they have lower precedence than '='.
That's why all your assignments are interpreted like this:
($a = false) or true;
Instead you should be using the normal && and || operators, those will be
correctly interpreted as
$a = (false || true);
The reason we have the lower-precedence variants is to allow things like
$result = mysql_query(...) or die(mysql_error());
This is obviously a very bad example, but probably also the one most used. It
basically allows you to combine an assignment with an error check.
This behavior is consistent with other languages that implement both the normal
|| and && operators as well as the OR and AND operators.
Previous Comments:
------------------------------------------------------------------------
[2012-12-27 10:37:13] rstoll at tutteli dot ch
Description:
------------
see test script. Seems like the weak logic operators do not have any effect.
My PHP version is 5.4.7
Was already mentioned in https://bugs.php.net/bug.php?id=46530&edit=2
Test script:
---------------
$a = false or true;
var_dump($a); //boolean false
$a = true or false;
var_dump($a); //boolean true - that's ok
$a = true xor true;
var_dump($a); //boolean true
$a = false xor true;
var_dump($a); //boolean false
$a = true and false;
var_dump($a); //boolean true
Expected result:
----------------
//or
boolean true
boolean true - this one worked as expected
//xor
boolean false
boolean true
//and
boolean false
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=63861&edit=1
