PHP Division By Zero? [closed] - php

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Two hours ago the following script worked. Now for some reason, I'm getting an error "Warning: Division by zero in _ on line 30". Here's the script. Can anyone tell me what I'm doing wrong and how to correct it?
Basically this script is pulling data from two elements on another website, dividing them to get a number which in turn is being used to set the width of an element. Been troubleshooting this for a while. Thanks so much in advance!
<?php
define("FFF_SIXDEGREES", "http://www.stayclassy.org/fundraise?fcid=257739");
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, FFF_SIXDEGREES);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
if(!($results = curl_exec($curl))) {
print("{ \"total\": \"$0.00\" }");
return;
}
$pattern = '/<li class="goalTitle">Raised so far:<\/li>\s*<li>\$([\d\.,]+)<\/li>/';
preg_match($pattern, $results, $matches);
$total = $matches[1];
$total = str_replace(",", "", $total);
// printf("<h2 class=\"raised-total\">$%s</h2>", formatMoney($total, true));
$pattern2 = '/<li class="goalTitle">My goal:<\/li>\s*<li>\$([\d\.,]+)<\/li>/';
preg_match($pattern2, $results, $matches);
$total2 = $matches[1];
$total2 = str_replace(",", "", $total2);
// printf("<h2 class=\"goal-total\">$%s</h2>", formatMoney($total2, true));
$diff = ($total/$total2) * 100; // THIS IS THE LINE OF CODE IN QUESTION
function formatMoney($number, $fractional=false)
{
if ($fractional) {
$number = sprintf('%.2f', $number);
}
while (true) {
$replaced = preg_replace('/(-?\d+)(\d\d\d)/', '$1,$2', $number);
if ($replaced != $number) {
$number = $replaced;
} else {
break;
}
}
return $number;
}
echo "<div class=\"progress-header\" style=\"width:$diff%;\"><span class=\"raised-amount\">$$total</span><span class=\"goal-amount\">$$total2</span></div>";
?>

Answer 1

The error message is helpfull here. On that line:
$diff = ($total/$total2) * 100;
the $total2 variable maybe sometime equal to 0, so php cannot execute the calculation (it's impossible to divide by zero). So you chould do somthing like this :
if($total2) // This condition will be true if $total2 != 0
$diff = ($total/$total2) * 100;
else
$diff = 0;
Also, I can see on your code that $total and $total2 are string, converted into float. This can be a source of error too. You should force the conversion to float using floatval :
if(floatval($total2))
$diff = ( floatval($total) / floatval($total2) ) * 100;
else
$diff = 0;

Answer 2

$total2 is 0 because you set wrong RegExp.
First, add i after last / in both patterns to change mode to case insensitive (you've got eg. Raised So Far on website but you're using Raised so far). Next, check what are you getting in your both $matches.

Answer 3

Given that it is actually only a warning and doesn't cause the script to stop, you can also use the following to simply hush the messages on that line:
<?php
$var=4;
$diff = (100/$var) * 100;
echo $diff."<br><br>";
$var=0;
$diff = (100/$var) * 100;
echo $diff."<br><br>";
$var=0;
$diff = #(100/$var) * 100; // Note the # symbol before the possible wanring
echo $diff."<br><br>";
?>
Output:
2500
Warning: Division by zero in C:\Server\www\test1.php on line 8
0
0
Basically, it will render as a zero. It's not the best way, but in terms of efficiency, if you are dealing with a lot of data, it might be better to not display the warning as compared to performing validation on each row of data.
It's probably not what I would do (though I have done it once) but I thought I would offer it as a suggestion.