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@NogDogApr 01.2005 — #My guess is that you're running into the vagaries of floating point arithmetic, which is notorious for having essentially unpredictable variances at the least significant digit level. If the underlying code for the number_format() function is doing any sort of arithmetic functions with the input number to determine how to round it, you're likely to run into this sort of thing. @NogDogApr 03.2005 — #It's not exactly "wrong", but it is inconsistent. The problem is that when a number like "10.205" is operated on in floating point arithmetic, you tend to end up with results in memory like 10.2050000000001 or 10.2049999999999.
Even number_format() and sprintf() don't give exact same results. This code...
...generates this output...
number_format/ round
Can anyone explain why is this happening ? number_format() function chooses to round off the second digit to “1” for the first three listed below, but does not do so for the last three. Round() function behaves the same way too.
Number format(10.205) : 10.21
Number format(11.205) : 11.21
Number format(15.205) : 15.21
Number format(16.205) : 16.20
Number format(19.205) : 19.20
Number format(20.205) : 20.20
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@NogDogApr 01.2005 — #0
@NogDogApr 03.2005 — #It's not exactly "wrong", but it is inconsistent. The problem is that when a number like "10.205" is operated on in floating point arithmetic, you tend to end up with results in memory like 10.2050000000001 or 10.2049999999999.Even number_format() and sprintf() don't give exact same results. This code...
[code=php]
$test = array(10.205, 11.205, 12.205, 13.205, 14.205, 15.205, 16.205, 17.205,
18.205, 19.205, 20.205, 21.205, 29.205);
foreach($test as $value)
{
echo sprintf("Test value = %s, number_format = %s, sprintf value = %.2fn",
$value, number_format($value,2), $value);
}
[/code]...generates this output...
<i>
</i>Test value = 10.205, number_format = 10.21, sprintf value = 10.21
Test value = 11.205, number_format = 11.21, sprintf value = 11.21
Test value = 12.205, number_format = 12.21, sprintf value = 12.21
Test value = 13.205, number_format = 13.21, sprintf value = 13.21
Test value = 14.205, number_format = 14.21, sprintf value = 14.21
Test value = 15.205, number_format = 15.21, sprintf value = 15.21
Test value = 16.205, number_format = 16.20, sprintf value = 16.20
Test value = 17.205, number_format = 17.20, sprintf value = 17.20
Test value = 18.205, number_format = 18.20, sprintf value = 18.20
Test value = 19.205, number_format = 19.20, sprintf value = 19.20
Test value = 20.205, number_format = 20.20, sprintf value = 20.20
Test value = 21.205, number_format = 21.21, sprintf value = 21.20
Test value = 29.205, number_format = 29.21, sprintf value = 29.20