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aslate · Apr 27th, 2005, 4:53 PM

I've been using fmod to validate data entry in Terry's Turkeys. You need to check weights are entered in 5g increments. So i take the input, *1000 and take the modulus for 5.

This threw up an odd bug when i inputted 8.065kg. Perfectly valid, as you can see. But rejected by my code. So i did a test:

(Toggle Plain Text)

for ($n = 0; $n < 10; $n += 0.005)
{
	$largen = $n*1000;
	$mod = $largen % 5;
	if (fmod(($largen), 5) != 0 || $largen % 5 != 0) 
	{ 
		echo "<tr><td>$n</td><td>$largen</td><td>".fmod(($largen), 5)."</td><td>".$mod."</td></tr>";
	}

You'll find the output rather odd: Results

Why's it doing this? It's not just fmod() being weird as it's for floating points, but % too.

Apr 27th, 2005, 4:53 PM	#1
aslate Newbie Join Date: Apr 2005 Posts: 1 Rep Power: 0	*$n 1000 and Mod** I've been using fmod to validate data entry in Terry's Turkeys. You need to check weights are entered in 5g increments. So i take the input, 1000 and take the modulus for 5. This threw up an odd bug when i inputted 8.065kg. Perfectly valid, as you can see. But rejected by my code. So i did a test: (Toggle Plain Text) for ($n = 0; $n < 10; $n += 0.005) { $largen = $n1000; $mod = $largen % 5; if (fmod(($largen), 5) != 0 \|\| $largen % 5 != 0) { echo "<tr><td>$n</td><td>$largen</td><td>".fmod(($largen), 5)."</td><td>".$mod."</td></tr>"; } for ($n = 0; $n < 10; $n += 0.005) { $largen = $n*1000; $mod = $largen % 5; if (fmod(($largen), 5) != 0 \|\| $largen % 5 != 0) { echo "<tr><td>$n</td><td>$largen</td><td>".fmod(($largen), 5)."</td><td>".$mod."</td></tr>"; } You'll find the output rather odd: Results Why's it doing this? It's not just fmod() being weird as it's for floating points, but % too.