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Request #53038 Enhancement / change to array_flip() with boolean values
Submitted: 2010-10-10 22:55 UTC Modified: 2020-12-07 16:07 UTC
Votes:2
Avg. Score:4.5 ± 0.5
Reproduced:2 of 2 (100.0%)
Same Version:1 (50.0%)
Same OS:1 (50.0%)
From: phplists at stanvassilev dot com Assigned:
Status: Suspended Package: Arrays related
PHP Version: 5.3.3 OS:
Private report: No CVE-ID: None
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 [2010-10-10 22:55 UTC] phplists at stanvassilev dot com
Description:
------------
This is not a bug, but I propose a change to how array_flip operates with 
boolean values, in order to improve common use cases, because:

1) The current behavior (warning and completely empty array) renders arrays with 
one or more boolean values invalid for flipping so they have to be manually 
filtered in advance.

2) When true/false are cast to 1/0, all loose type checks against the keys will 
match (i.e. true == 1, false == 0) which makes the cast also a practical one for 
real utility.

3) The change will make the casting behavior of array_flip consistent with the 
*already* existing behavior in the following example:

// casts booleans to int, and produces: array(1 => 123, 0 => 321);
$a = array(); $a[true] = 123; $a[false] = 321;




Test script:
---------------
var_dump(
    array_flip(
        array('foo' => true, 'bar' => false)
    )
);

Expected result:
----------------
array(2) { [1]=> string(3) "foo" [0]=> string(3) "bar" }

Actual result:
--------------
Warning: array_flip() [function.array-flip]: Can only flip STRING and INTEGER 
values! in ... on line 2

array(0) { }

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AllCommentsChangesGit/SVN commitsRelated reports
 [2010-12-01 15:23 UTC] jani@php.net
-Package: *General Issues +Package: Arrays related -Operating System: Any +Operating System:
 [2020-12-07 16:07 UTC] cmb@php.net
-Status: Open +Status: Suspended
 [2020-12-07 16:07 UTC] cmb@php.net
This feature would have very limited usefulness, since in case of
more than two boolean values, elements would inevitably
overwritten.  If you, or anybody else, still feels that this would
be a generally useful improvement, please write to the internals
mailing list to start a discussion.  For the time being, I'm
suspending this ticket.
 
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