strange bug calculating floats.

[Hawk2005]

Hi,

this code doesn't work correctly:

<?
$i = 0.00;
$i += 5.99;
$i += 20.00;
$i -= 20.00;
$i -= 5.99;
echo $i."<br>";
?>

output: 1.7763568394E-015

Any ideas ? Why does this happen ?

cu...

[LordShryku]

No idea why this happens, but it does work using the [man]bcmath[/man] functions

[Hawk2005]

Thanks...

this helped.

But anybody got ideas why this happens ?!?

typecast error from string to float?

$i = 5.99;

Is $i already float ? or is it string until an oparator is used ?

cu...

[drawmack]

It looks like an archaic rounding error to me

[Weedpacket]

Looks like a floating-point rounding error to me as well (1/100 does not have a terminating binary expansion); generally it's more reliable to scale everything up into integers, work there, and then scale back afterwards.