PHP Warning: Division by zero

[brokaddr]

This seems like such an easy to comprehend error message - however, when I view the page in question, I cannot replicate the error.

The error line trigger is as follows:

if( $i && (($i+1)%$divideby) == 0 ) {

Clearly I am missing an isset() or !== but I am not sure which/where to put it?

[lucy24]

Obvious first question (in any language): what is the prior history of $divideby?

[brokaddr]

It's a mysql_num_rows call. I've tested that, and there is a number present.

[swa66]

Any chance there's a query that doesn't return any rows ?

Calculating the remainder of something divided by zero isn't going to work out...
You should check that you get a $divideby that's different from zero before you calculate the modulo.

[brokaddr]

No, there's always at least 1 result.

Would if($divideby>0) work?

[penders]

That should work, if $divideby is always an integer. Bear in mind that (N % 0.9) would also result in a divide by zero warning (the operands are first converted to integers).

Although if $divideby (the result of a SQL expression) should always be >= 1 then it looks as if something earlier in your code is failing.