Bug #54740 [Com]: Ternary operator will not work with return by reference
Edit report at https://bugs.php.net/bug.php?id=54740&edit=1
ID: 54740
Comment by: marrch dot caat at gmail dot com
Reported by: dukeofgaming at gmail dot com
Summary: Ternary operator will not work with return by
reference
Status: Not a bug
Type: Bug
Package: Scripting Engine problem
PHP Version: Irrelevant
Block user comment: N
Private report: N
New Comment:
Mike, I understand that. The second note tells I caanot return a reference to an expression result,
such as &$object->method() or &(new StdClass()) - I can understand that. But the code
sample I provided doesn't try to do that. To make things even simplier, the following code
still fails to compile:
$link = $flag ? &$a : &$b;
It doesn't try to return a reference to an expression, just a reference to a viriable; It
doesn't try doing anything that the following code doesn't:
if ($flag)
$link = &$a;
else
$link = &$b;
And maybi I'm really stupid, but after 10 years in PHP development I still don't
understand why the first code cannot be compiled :(
Previous Comments:
------------------------------------------------------------------------
[2013-10-02 05:27:05] mike@php.net
I meant the documentation "Note:" (warning) not the user-contributed note.
------------------------------------------------------------------------
[2013-10-01 20:35:33] marrch dot caat at gmail dot com
I thoroughly read the article you mentioned, Mike, but still don't understand why the following
code fails to compile:
$link = isset($i) ? (& $arr[$i]) : null;
- while the following works fine:
$link = &$arr[$i];
In this case, &$arr[$i] is a legal reference assignment, so the first code should behave equal
to
if (isset($i)) {
$link = &$arr[$i];
} else {
$link = null;
}
- but this code works fine, and mentioned above isn't even compiled. What's wrong with it?
------------------------------------------------------------------------
[2013-10-01 14:42:02] mike@php.net
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to
report
a bug at http://bugs.php.net/how-to-report.php
Check the second note here:
http://php.net/manual/en/language.references.return.php
------------------------------------------------------------------------
[2012-08-27 14:17:44] marrch dot caat at gmail dot com
This is a general problem with reference inside ternary operator. For ex., the following script
fails with the same error:
$link = isset($i) ? (& $arr[$i]) : null;
- while the following works fine:
$link = & $arr[$i];
------------------------------------------------------------------------
[2011-05-15 22:59:17] dukeofgaming at gmail dot com
Description:
------------
PHP fails to parse a returned by reference value when using the ternary operator.
The test script provided illustrates a case of when it is absolutely necessary
to return by reference; if the "&" is removed then the output would be a fatal
error: "Fatal error: Cannot use [] for reading in <...>"
Test script:
---------------
$value = ($condition)?(
$some_value
):(&$object->Collection[]);
Expected result:
----------------
No errors, should be the equivalent of having:
if($condition){
$value = $some_value;
}else{
$value = &$object->Collection[];
}
Actual result:
--------------
Parse error: syntax error, unexpected '&' in <...>
------------------------------------------------------------------------
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Thread (8 messages)