ID: 17282
Updated by: [EMAIL PROTECTED]
Reported By: [EMAIL PROTECTED]
Status: Bogus
Bug Type: Scripting Engine problem
Operating System: FreeBSD 4.4-STABLE
PHP Version: 4.2.1
New Comment:
That does not seem right. The numbers appear to be exactly the same.
Even if they can't be compared as floats, comparing untyped should
work, because they look exactly the same (when var_dump'd and
printed).
Even if this is in fact bogus, it needs to be documented.
I am well aware that there can be errors due to loss of precision, but
in that case, the number should not appear to be _exactly the same_.
There should be some way to tell that they are different.
Previous Comments:
------------------------------------------------------------------------
[2002-05-17 02:16:22] [EMAIL PROTECTED]
You can't compare floats like this, a float is an approximation of the
number, but never exact the number.
This is not a bug, this wouldn't work in most languages, including C ->
Bogus
------------------------------------------------------------------------
[2002-05-16 22:23:02] [EMAIL PROTECTED]
This problem also occurs on PHP 4.1.2.
The following code fragment produces very odd results:
<?
$a = array(41.96, 20.97, 20.99);
$t = 0;
for($i = 1; $i < count($a); $i++)
$t += abs($a[$i]);
echo "$t != $a[0]\n";
var_dump($t != $a[0]);
echo "t = ";
var_dump($t);
echo "a[0] = ";
var_dump($a[0]);
?>
The results are shown below:
41.96 != 41.96
bool(true)
t = float(41.96)
a[0] = float(41.96)
Both variables appear to be the same type, and look the same, yet
compare incorrectly with both typed and untyped comparisons.
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Edit this bug report at http://bugs.php.net/?id=17282&edit=1
