Bug #44999 [Com]: 0 equals any string
Edit report at https://bugs.php.net/bug.php?id=44999&edit=1 ID: 44999 Comment by: radamanf at gmail dot com Reported by:ethan dot nelson at ltd dot org Summary:0 equals any string Status: Not a bug Type: Bug Package:Scripting Engine problem Operating System: windows 2003 PHP Version:5.2.6 Block user comment: N Private report: N New Comment: I can see that it's no any logical explanation to keep this BUG unfixed! Status: Not a bug -> why??? It's not funny, so many years past. I do love to use PHP and like that no needed to define variable types, but this is generic FAIL. Come one guys, someone need to fix this, please. My PHP version PHP 5.3.10-1ubuntu3.5 with Suhosin-Patch (cli) (built: Jan 18 2013 23:45:59) Previous Comments: [2012-08-24 08:16:07] bugs dot php dot net at simoneast dot net This is quite ridiculous. Can this 'feature' of PHP *please* be reconsidered? [2008-05-14 22:25:51] ethan dot nelson at ltd dot org I don't recall PHP ever behaving that way. So how do you alter a switch statement to use the identical operator instead of equivalency? It seems somewhat odd that any text character would be equvalent to integer 0. As I remember the chart it was something like: 0 == '0' true 0 == '' true 0 == null true 0 == false true 0 == 'text' false Basically if we are going to treat any string as equivalent to 0, the switch statement becomes useless when iterating through arrays unless you first strip key names of integer 0. [2008-05-14 22:20:01] cel...@php.net see Bug #44990 for explanation [2008-05-14 21:51:49] ethan dot nelson at ltd dot org Description: Right now, 0 compared to any string will prove true. Reproduce code: --- Expected result: False Actual result: -- True -- Edit this bug report at https://bugs.php.net/bug.php?id=44999&edit=1
Bug #44990 [Com]: array('word')==array(0) -- true
Edit report at https://bugs.php.net/bug.php?id=44990&edit=1
ID: 44990
Comment by: radamanf at gmail dot com
Reported by:design at apostolstudio dot com
Summary:array('word')==array(0) -- true
Status: Not a bug
Type: Bug
Package:Scripting Engine problem
Operating System: Windows XP
PHP Version:5.2.6
Block user comment: N
Private report: N
New Comment:
Comparison === needed ONLY if, during type conversion, we got same values, so
String compare to Integer should be compared using Integer converted to string
and check if they are equal.
So if String is '' and Int is 0
or '1' == 1
'2' == 2
.. etc. only in this cases === is necessary to tell VARIABLE TYPE difference.
It's so obvious, why I'm explaining all this to you ?! You should know this
better than me! Please fix this BUG
Previous Comments:
[2008-05-14 02:58:01] design at apostolstudio dot com
Thanks for explanations.
[2008-05-14 02:39:53] cel...@php.net
use ===
'word' is converted to an integer for the comparison, and thus 0 == 0.
try this code:
if(array('word')===array(0)) echo "ERROR";
[2008-05-14 02:27:10] design at apostolstudio dot com
Description:
array('word')==array(0) -- return true
Reproduce code:
---
if(array('word')==array(0)) echo "ERROR";
Actual result:
--
ERROR
--
Edit this bug report at https://bugs.php.net/bug.php?id=44990&edit=1
Bug #39579 [Com]: Comparing zero & string values in boolean comparison has unexpected behaviour
Edit report at https://bugs.php.net/bug.php?id=39579&edit=1 ID: 39579 Comment by: radamanf at gmail dot com Reported by:iain at workingsoftware dot com dot au Summary:Comparing zero & string values in boolean comparison has unexpected behaviour Status: Not a bug Type: Bug Package:Variables related Operating System: FreeBSD 6.1 PHP Version:5.2.0 Block user comment: N Private report: N New Comment: This is a epic FAIL in pure logic of comparing formats not having explicitly defining them, whole beauty of PHP disappear! This is BROKEN LOGIC. Connected BUGS Bug #44990 Bug #39579 Different people are coming across this BUG and thinking the same as me, so please CHANGE your documentation, it's WRONG! Who is this "GENIES" to make possible converting String to Integer NOT INT TO STRING! Guys, I'm very disappointed! :) Previous Comments: ---- [2013-02-14 17:14:35] radamanf at gmail dot com This is a epic FAIL in pure logic of comparing formats not having explicitly defining them, whole beauty of PHP disappear! This is BROKEN LOGIC. Connected BUGS Bug #44990 Bug #39579 Different people are coming across this BUG and thinking the same as me, so please CHANGE your documentation, it's WRONG! Who is this "GENIES" to make possible converting String to Integer NOT INT TO STRING! Guys, I'm very disappointed! :) [2012-08-01 10:31:16] v dot picture at free dot fr Hi, I'm wondering why this comparison should be evaluated in a numeric context and not a string context, after all there is no loss with string casting whereas there is a huge risk of doing mistakes with numeric casting: (string) 0 => "0" (string) 42.5 => "42.5" (int) "test" => 0 But ok, let's say it's a normal behavior. "If you compare a number with a string or the comparison involves numerical strings, then each string is converted to a number" Then why would PHP decide to do that in a string context ? I mean, when I compare two strings I don't expect PHP to convert everything to numbers ! "10" == "1e1" => true Sorry folks, this really seems like a string context to me. [2006-11-22 11:36:19] m...@php.net It's not a problem -- it's a feature, and it's documented at the address I've just quoted, which describes evaluation of a string in any numeric context. [2006-11-22 11:14:47] iain at workingsoftware dot com dot au it's not the behaviour of how a string is cast to an integer that i'm talking about, but if i have a comparison: if($value == Class::CONSTANT) and the class constant is a string, it's not immediately apparent that if $value == 0 then this will evaluate to true. maybe warning is too strong, but a notice might be good in the event that a non-strict == operation returns true because one of the operands is 0 and the other operand is a value that evaluates to 0 when cast as an int. anyway, i guess if php has been around for this long without anyone mentioning it yet ... i mean, this is the first time i've come across the problem. if a notice had been emitted it would have been a time saver. [2006-11-22 11:06:57] m...@php.net And, besides, this behaviour is documented at http://www.php.net/manual/en/language.types.string.php#language.types.string.conversion The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=39579 -- Edit this bug report at https://bugs.php.net/bug.php?id=39579&edit=1
Bug #39579 [Com]: Comparing zero & string values in boolean comparison has unexpected behaviour
Edit report at https://bugs.php.net/bug.php?id=39579&edit=1
ID: 39579
Comment by: radamanf at gmail dot com
Reported by:iain at workingsoftware dot com dot au
Summary:Comparing zero & string values in boolean comparison
has unexpected behaviour
Status: Not a bug
Type: Bug
Package:Variables related
Operating System: FreeBSD 6.1
PHP Version:5.2.0
Block user comment: N
Private report: N
New Comment:
I've seen a topic in the web:
http://josephscott.org/archives/2012/03/why-php-strings-equal-zero/ related to
this bug, and I can see that sometimes string need to be compared with integer
as integer BUT this is a huge pool of potential bugs across all the worldwide!
:) Can you imagine how many people usign PHP without realizing this BUG ! :)_)
I'm sure this is a loved BUG by most hackers out there !
Previous Comments:
[2013-02-14 17:24:51] ni...@php.net
@radamanf: Stop shouting. Shouting does not help.
I agree that this behavior ('foo' == 0) is counter-productive. I think most
people would agree on that. But even if everyone agrees that it's the wrong
behavior, changing it isn't so easy. Changing this behavior will probably break
existing software.
If you really want to change this, then there is only one way: Make the change
and then test a shitload of code against it. See how many tests will fail in
major PHP projects and how easy things are to fix.
If you can provide sufficient data that this change (which goes rather deep
into the core semantics of the language) won't affect existing projects
heavily, then I see no problem with doing it.
--------
[2013-02-14 17:14:35] radamanf at gmail dot com
Related To: Bug #39579
--------
[2013-02-14 17:14:35] radamanf at gmail dot com
This is a epic FAIL in pure logic of comparing formats not having explicitly
defining them, whole beauty of PHP disappear! This is BROKEN LOGIC.
Connected BUGS
Bug #44990
Bug #39579
Different people are coming across this BUG and thinking the same as me, so
please CHANGE your documentation, it's WRONG! Who is this "GENIES" to make
possible converting String to Integer NOT INT TO STRING!
Guys, I'm very disappointed! :)
[2012-08-01 10:31:16] v dot picture at free dot fr
Hi, I'm wondering why this comparison should be evaluated in a numeric context
and not a string context, after all
there is no loss with string casting whereas there is a huge risk of doing
mistakes with numeric casting:
(string) 0 => "0"
(string) 42.5 => "42.5"
(int) "test" => 0
But ok, let's say it's a normal behavior.
"If you compare a number with a string or the comparison involves numerical
strings, then each string is converted to
a number"
Then why would PHP decide to do that in a string context ? I mean, when I
compare two strings I don't expect PHP to
convert everything to numbers !
"10" == "1e1" => true
Sorry folks, this really seems like a string context to me.
[2006-11-22 11:36:19] m...@php.net
It's not a problem -- it's a feature, and it's documented at the address I've
just quoted, which describes evaluation of a string in any numeric context.
The remainder of the comments for this report are too long. To view
the rest of the comments, please view the bug report online at
https://bugs.php.net/bug.php?id=39579
--
Edit this bug report at https://bugs.php.net/bug.php?id=39579&edit=1
Req #39579 [Com]: Comparing zero & string values in boolean comparison has unexpected behaviour
Edit report at https://bugs.php.net/bug.php?id=39579&edit=1
ID: 39579
Comment by: radamanf at gmail dot com
Reported by:iain at workingsoftware dot com dot au
Summary:Comparing zero & string values in boolean comparison
has unexpected behaviour
Status: Not a bug
Type: Feature/Change Request
Package:Variables related
Operating System: FreeBSD 6.1
PHP Version:5.2.0
Block user comment: N
Private report: N
New Comment:
Hi Nick, Thanks for your answers on both related bugs.
I apologize for my expressions.
But I'm still thinking this bug should be fixed one day, maybe on later day
when a few backwards compatible bugs will be found, so it makes more sense to
fix it as a bunch. I hear that PHP 5.3 was breaking release and some old code
was not working since, it was the right time to fix this bug.
The general logic should be: Convert less complicated variable type into more
complicated type, so convert Int up to String not bringing String down to Int.
This need to be universal and according to KISS logic. If geeks need to use
strings for octal or hexadecimal then they know what they are doing and need to
cast such string as Int! To bring string down to Int.
v dot picture at free dot fr ->
"
Then why would PHP decide to do that in a string context ? I mean, when I
compare two strings I don't expect PHP to
convert everything to numbers !
"10" == "1e1" => true
Sorry folks, this really seems like a string context to me.
"
Someone need to write a great exploit to hack into eCommerce shops and produce
unseen damage across the Globe :) then this will not be funny at all.
I wish this patch could happen one day! Temporarily it could be at least a
Warning, Iain suggested to give a notice, but I believe this bug got a great
hidden potential.
Previous Comments:
[2013-02-14 22:52:25] iain at workingsoftware dot com dot au
Sorry I meant to submit this as "Feature/Change Request" but submitted the form
without a password and it changed back to "bug".
[2013-02-14 22:50:15] iain at workingsoftware dot com dot au
Hi, I agree this shouldn't be changed. It's pretty fundamental to how PHP works
and since reporting this bug 6
years ago I've learned a lot more about PHP :)
I still think my suggestion of emitting a Notice whenever a string is converted
to 0 as a result of being
evaluated in a numeric context isn't too outlandish though.
*Changing* the way that strings are evaluated would break a buttload of code
and
isn't really productive.
Emitting a Notice would help people unfamiliar with the implicit typecasting
behaviour save some time and
avoid bugs when developing. For those that like to write "clean code" with no
Notices there is a very simple
way of suppressing it (ie. use === or (int)).
Also, emitting a notice wouldn't actually break any code, although it might
cause a number of scripts out in
the wild to become more verbose in their logging - is that not an acceptable
risk?
The notice could even say something like:
Notice: String evaluated to 0 (zero) when used in numeric context on line
WHATEVER. Use === or (int) to
prevent this notice.
This would enable people to quickly understand the behaviour (which is kind of
unintuitive but fair enough
when you look at PHPs type system - just a foible of the language everyone
should learn) and encourage people
to learn the importance of === earlier on.
--------
[2013-02-14 17:26:40] radamanf at gmail dot com
I've seen a topic in the web:
http://josephscott.org/archives/2012/03/why-php-strings-equal-zero/ related to
this bug, and I can see that sometimes string need to be compared with integer
as integer BUT this is a huge pool of potential bugs across all the worldwide!
:) Can you imagine how many people usign PHP without realizing this BUG ! :)_)
I'm sure this is a loved BUG by most hackers out there !
[2013-02-14 17:24:51] ni...@php.net
@radamanf: Stop shouting. Shouting does not help.
I agree that this behavior ('foo' == 0) is counter-productive. I think most
people would agree on that. But even if everyone agrees that it's the wrong
behavior, changing it isn't so easy. Changing this behavior will probably break
existing software.
If you really want to change this, then there is only one way: Make the change
and then test a shitload of code against it. See how many tests will fail in
major PHP projects and how easy things are to fix.
If you can provide sufficient data t
