Problem dividing PHP variables?!

Ziycon

Im retrieving two integer values from a db and they are both printing to screen fine but when i try to divide one by the other i get this error:

Warning: Division by zero in C:\Apache\htdocs\dn\cl_desc.php on line 128

This is what i have on line 128, id number is just an id number for the row, but it shud just divide the two integers that both methods return:
Code:

<?php $total = rating_cl($id_num) / voters_cl($id_num); echo $total; ?>

Adam

Theres obviously a problem with the functions. More code is needed here to debug methinks.

Ziycon

function rating_cl($c)
{
	$sql = 'SELECT vote FROM cl WHERE id='.$c.'';
	$data = mysql_query($sql);
	while ($row = mysql_fetch_assoc($data)) 
	{
   		echo $row['vote'];
	}
}
function voters_cl($c)
{
	$sql = 'SELECT voters FROM cl WHERE id='.$c.'';
	$data = mysql_query($sql);
	while ($row = mysql_fetch_assoc($data)) 
	{
   		echo $row['voters'];
	}
}

heres the two functions that are being called but its not them as they are returning the right data and printing them onto the website fine, its just the divide bit thats causing an error for some reason!?!

DonkeyStyle \o/

[edit] oops too late

Adam

You're using $c in the functions, where is $id_num being set?

I've mocked up some functions and tested it like this, and it works:

[php]

<?php


$id_num = "6";


function rating_cl($id_num) {

$id_num = $id_num * '5';

return $id_num;

}

function voters_cl($id_num) {

$id_num = $id_num / '3';

return $id_num;

}

echo "rating_cl is ".rating_cl($id_num)."<br />";

echo "voters_cl is ".voters_cl($id_num)."<br />";

$total = rating_cl($id_num) / voters_cl($id_num);

echo $total;



?>

[/php]

Ziycon

EDIT:

Did it print out the division answer?

Adam

Nope, no error using that. But why would there be, it's merely an alteration on the echo call, none of the calculation code is changed.

EDIT: Yeah, the code I posted above works. As I said, where and how is $id_num being defined?

Ziycon

Sorted it! The problem was in the functions, they were echoing the result and the division operator didn't like it, so i just returned the values from the function and it works fine now!
Thanks for the help!

Adam

Shít yeah, I should have noticed that, you needed to return the values rather than print them! No problem anyway!

democrates

It would be prudent to always check a value is non-zero before attempting to divide anything by it, and if it's zero to present a relevant message such as "No voters yet".

Ziycon

democrates wrote:

It would be prudent to always check a value is non-zero before attempting to divide anything by it, and if it's zero to present a relevant message such as "No voters yet".

I know but ther values where never zero, its just as i said the values where being echoed instead or returned!

daymobrew

Ziycon wrote:

I know but ther values where never zero, its just as i said the values where being echoed instead or returned!

You should consider the case when the query doesn't return any rows i.e. when the id ($c) is invalid. Returning 0 from the function might be a good error value then.