Edit report at https://bugs.php.net/bug.php?id=64324&edit=1
ID: 64324
Updated by: ras...@php.net
Reported by: dosergio at ig dot com dot br
Summary: Why 0 == 'BOOK' ?
Status: Not a bug
Type: Bug
Package: *General Issues
Operating System: all
PHP Version: Irrelevant
Block user comment: N
Private report: N
New Comment:
No it doesn't make more sense. This would make 12=='TEST'
You cast to a type in the comparison, not to some third type. Besides changing
this would break millions of lines of code. Not going to happen.
Previous Comments:
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[2013-03-02 01:19:42] dosergio at ig dot com dot br
A good rule to be implemented by PHP is:
If a comparison of simple equality ( == ) or simple inequality ( != ) is done
between two different data types, PHP should cast both to boolean before
comparing.
Because 'TEXT' casts to true, 0 casts to false so 0 != 'TEXT' makes more sense
than 0 == 'TEXT'.
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[2013-02-28 19:12:25] dosergio at ig dot com dot br
OK, you are right. That was the explanation I wanted: it depends on the type
you compare.
if( false == 'TEST') works correctly.
Now it makes a little more sense to me.
But javascript is still superior because inside a if() I suspect that any
language should try to cast both to boolean.
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[2013-02-28 19:04:24] ras...@php.net
We don't want a special case for 0. By your logic 12 == 'TEST' should be true.
You are assuming a cast to boolean even though neither side of the comparison
is
a boolean. Note that true == 'TEST' will match because here we cast to boolean.
But 'TEST' cast to an integer is going to give you 0.
------------------------------------------------------------------------
[2013-02-28 18:58:51] dosergio at ig dot com dot br
Conclusion:
The exact analysis above done in javascript says I am right.
I have no doubt that javascript makes more use of logic that php.
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[2013-02-28 18:51:56] dosergio at ig dot com dot br
I know the use of ===. The supposed 'bug' that I think exists, is comparing 0
to a non-empty String with double ==
My concern is because:
Observation 1: null, 0, "0", and "" all result as FALSE.
Observation 2: BUT... "A STRING" evaluates as TRUE.
SO...
0 == "" makes sense
BUT...
0 == "A NON-EMPTY STRING" makes no sense. IMHO False would be the right answer.
Take a little time to examine this:
if( 0 ) echo "0 works as TRUE<br>"; else echo "0 works as false <br>";
if( "TEST") echo "'TEST' works as TRUE<br>"; else echo "'TEST' works as false
<br>";
if( 0 == 'TEST') echo "But 0 == 'TEST' belies the statements above!";
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