[PHP-DOC] #26821 [Bgs]: if(NANC 0) - always evaluates TRUE
ID: 26821 User updated by: ivo at benetech dot org Reported By: ivo at benetech dot org Status: Bogus Bug Type: Documentation problem Operating System: Linux / RH 7.3 PHP Version: 4.3.4 New Comment: If someone asks you if A+B 4 is, you wouldn't know what to calculate... I sincerely hope this would hold: http://www.php.net/manual/en/language.operators.php#language.operators.precedence otherwise theres bigger problems. If a statement such as some arbitrary string 0 is not to be trusted then the documentation should be updated to reflect this. Currently it explains strong comparisons with '===', weak with '==' but it does not mention or , ony obliquely and it obviously does not. (http://www.php.net/manual/en/types.comparisons.php) p.s. I am working with a site that manipulates strings everywhere. most functions return 0 on error or the processed string if all goes well. just finished updting it to return ints always use references for strings. still think it's an outright bug or at least a documentation problem due to all the 'weak' type comparison references examples everywhere. Previous Comments: [2004-01-09 11:04:29] [EMAIL PROTECTED] Who wants to evaluate NANC 0??? It _absolutely_ makes no sense. If someone asks you if A+B 4 is, you wouldn't know what to calculate... FYI I've tried ivo's script. Under PHP 4.3.3 it produces should happen...but doesnt and under 4.3.0 it's should not happen...but does. [2004-01-08 22:35:09] skissane at ics dot mq dot edu dot au Vrana: your comment makes no sense. If NANC is converted to 0, then 0 0 would be FALSE, not true. Compare these expressions: NANC 0result TRUE NANC 0 result FALSE 0 0 result FALSE So it seems it is neither converting NANC to an integer 0, nor 0 to a string 0. What actually is going on? The documentation should clarify this. [2004-01-07 13:20:58] ivo at benetech dot org It also print 0 as expected. if( (int) NANC 0) also evaluates as expected. [2004-01-07 05:53:18] [EMAIL PROTECTED] NANC is converted to 0 for comparison. It works for me as expected. What is printed by the code ?php echo intval(NANC); ? on your system? [2004-01-06 18:08:12] ivo at benetech dot org Documentation needs to be more explicit about php being strongly typed. http://www.php.net/manual/en/language.types.type-juggling.php or 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 http://bugs.php.net/26821 -- Edit this bug report at http://bugs.php.net/?id=26821edit=1
[PHP-DOC] #26821 [Bgs]: if(NANC 0) - always evaluates TRUE
ID: 26821
Updated by: [EMAIL PROTECTED]
Reported By: ivo at benetech dot org
Status: Bogus
Bug Type: Documentation problem
Operating System: Linux / RH 7.3
PHP Version: 4.3.4
New Comment:
As said by sniper: never ever compare different types like that!!!
In case $var is an int, you can do a $var 0. In case $var is a
string, PHP don't know what to do (try this with Java or C++!).
Let your called functions return FALSE on error and everything works
fine. Or as an alternative, try something like
$var=somefunction();
if(is_integer($var)$var0)
{
// Here comes the error-Processing
print(Error\n);
}
else
{
// Do something with $var
print $var;
}
Previous Comments:
[2004-01-09 11:32:01] ivo at benetech dot org
If someone asks you if A+B 4 is, you wouldn't know what to
calculate...
I sincerely hope this would hold:
http://www.php.net/manual/en/language.operators.php#language.operators.precedence
otherwise theres bigger problems.
If a statement such as
some arbitrary string 0
is not to be trusted then the documentation should be updated to
reflect this. Currently it explains strong comparisons with '===', weak
with '==' but it does not mention or , ony obliquely and it
obviously does not.
(http://www.php.net/manual/en/types.comparisons.php)
p.s. I am working with a site that manipulates strings everywhere. most
functions return 0 on error or the processed string if all goes well.
just finished updting it to return ints always use references for
strings.
still think it's an outright bug or at least a documentation problem
due to all the 'weak' type comparison references examples everywhere.
[2004-01-09 11:04:29] [EMAIL PROTECTED]
Who wants to evaluate NANC 0??? It _absolutely_ makes no sense. If
someone asks you if A+B 4 is, you wouldn't know what to calculate...
FYI I've tried ivo's script. Under PHP 4.3.3 it produces should
happen...but doesnt and under 4.3.0 it's should not happen...but
does.
[2004-01-08 22:35:09] skissane at ics dot mq dot edu dot au
Vrana: your comment makes no sense. If NANC is converted to 0, then 0
0 would be FALSE, not true.
Compare these expressions:
NANC 0result TRUE
NANC 0 result FALSE
0 0 result FALSE
So it seems it is neither converting NANC to an integer 0, nor 0 to a
string 0. What actually is going on? The documentation should clarify
this.
[2004-01-07 13:20:58] ivo at benetech dot org
It also print 0 as expected.
if( (int) NANC 0)
also evaluates as expected.
[2004-01-07 05:53:18] [EMAIL PROTECTED]
NANC is converted to 0 for comparison. It works for me as expected.
What is printed by the code ?php echo intval(NANC); ? on your
system?
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
http://bugs.php.net/26821
--
Edit this bug report at http://bugs.php.net/?id=26821edit=1
[PHP-DOC] #26821 [Bgs]: if(NANC 0) - always evaluates TRUE
ID: 26821
User updated by: ivo at benetech dot org
Reported By: ivo at benetech dot org
Status: Bogus
-Bug Type: Scripting Engine problem
+Bug Type: Documentation problem
Operating System: Linux / RH 7.3
PHP Version: 4.3.4
New Comment:
Documentation needs to be more explicit about php being strongly
typed.
http://www.php.net/manual/en/language.types.type-juggling.php
or
http://www.php.net/manual/en/language.types.string.php#language.types.string.conversion
Previous Comments:
[2004-01-06 17:23:58] [EMAIL PROTECTED]
RTFM:
http://www.php.net/manual/en/types.comparisons.php
(never ever compare different types like that)
[2004-01-06 16:28:47] ivo at benetech dot org
Description:
The statement...
if(NANC 0)
...always evaluates TRUE.
Reproduce code:
---
if(NANC 0)
{
print(should not happen...but does\n);
}
else
{
print(should happen...but doesnt\n);
}
Expected result:
echoed to the console:
should happen...but doesnt
Actual result:
--
echoed to the console:
should not happen...but does
--
Edit this bug report at http://bugs.php.net/?id=26821edit=1
