Edit report at http://bugs.php.net/bug.php?id=52825&edit=1
ID: 52825
Updated by: cataphr...@php.net
Reported by: mbroxer at post dot ru
Summary: return by reference with ternary operator causes
notice "Only variable..."
-Status: Open
+Status: Bogus
Type: Bug
Package: *General Issues
Operating System: Windows XP SP3
PHP Version: 5.3.3
Block user comment: N
New Comment:
return $key > 0 ? $this->a[$key] : $this->b[$key];
is the same as
return ($key > 0 ? $this->a[$key] : $this->b[$key]);
C is not comparable because it has only pass and return by value.
This is documented in http://pt.php.net/ternary :
Note: Please note that the ternary operator is a statement, and that it
doesn't evaluate to a variable, but to the result of a statement. This
is important to know if you want to return a variable by reference. The
statement return $var == 42 ? $a : $b; in a return-by-reference function
will therefore not work and a warning is issued in later PHP versions.
See also
http://stackoverflow.com/questions/3389928/can-you-pass-by-reference-while-using-the-ternary-operator/3390182#3390182
Previous Comments:
------------------------------------------------------------------------
[2010-09-13 06:46:55] mbroxer at post dot ru
I'm sorry, the expected result and actual result got mixed up when I was
submitting. Expected is actual, and actual is expected.
------------------------------------------------------------------------
[2010-09-13 06:45:41] mbroxer at post dot ru
Description:
------------
I don't know if it's a bug, or that's how it should be, but it would be
logical to assume that a ternary operator is equal to an IF block:
return $a ? $b : $c;
// ==
if ($a) return $b; else return $c;
I believe that's how it is in C. However when returning a reference, the
first version produces a notice:
"Notice: Only variable references should be returned by reference"
It's hard to tell if this is normal behaviour or not, but it's
confusing. If this is normal functionality, then I think this should be
in documentation, at least in a form of a comment.
Test script:
---------------
class test {
private $a = array();
private $b = array();
function &getA($key) {
return $key > 0 ? $this->a[$key] : $this->b[$key];
// the following line gives no notice
// if ($key > 0) return $this->a[$key]; else return
$this->b[$key];
}
}
$a = new test;
$b = &$a->getA('1');
Expected result:
----------------
Notice: Undefined index: 1 in - on line 9
Notice: Only variable references should be returned by reference in - on
line 9
Actual result:
--------------
Notice: Undefined index: 1 in - on line 9
------------------------------------------------------------------------
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Edit this bug report at http://bugs.php.net/bug.php?id=52825&edit=1
