Division by zero

[Dusaro]

Well, I am currently working on a Kill/Death Table when the players insert there kills and deaths along with a screenshot of proof.

I have got most of it down except for a Warning: Division by zero in /home/a2186214/public_html/table/index.php on line 43 error.

 

This is the code I am using to calculate the kill/deaths:

if ($row['kills'] >= 1)
{
$kdr = $row['kill']/$row['death'];
}
elseif ($row['death'] >= 1)
{
$kdr = $row['kill']/$row['death'];
}
else
$kdr = '0';

How would I fix this?

[xyph]

You need to make sure $row['death'] != 0 before you use it in a division statement

[btellez]

Looks to me like you mean this:

if ($row['kills'] >= 1 && $row['death'] >= 1){	
$kdr = $row['kill']/$row['death'];
} else {
$kdr = '0';
}

[Dusaro]

if i was to use both of your answers, i get this:

This now gives the Kill/Death at 0

if ($row['kills'] != 0 && $row['death'] != 0){	
$kdr = $row['kill']/$row['death'];
} else {
$kdr = '0';
}

 

If I try this:

It still shows as Kill/Death at 0.

if ($row['kills'] >= 1 && $row['death'] >= 1){	
$kdr = $row['kill']/$row['death'];
} else {
$kdr = '0';
}

 

So these are fixing the division by 0 error but it is not calculating the kill/death.

[btellez]

Well what value do your variables hold ?

[Psycho]

For a kill/death ratio (KDR) the 'death' is the divisor and is the only value that cannot be zero. However, if the 'kill' value is zero, then the KDR will be zero - which can be used in the calculation. So, there is no need to add special handling for the kill value.

 

The problem you have is if the 'death' value is zero. In that instance there really is no KDR that can be calculated. As you get smaller and smaller values for death as they approach zero, the KDR will approach infinity.

 

I have seen games that simply report no KRD when the user had no deaths or report a KDR based upon one death. I think the latter 'looks' better. But, this is a judgement call because when there are no deaths there is no real KDR value.

 

So, to use a default of 1 death when the deaths are zero becomes a very trivial solution.

if ($row['death'] == 0) { $row['death'] = 1; }
$kdr = $row['kill'] / $row['death'];

 

The only other - legitimate - options are to show no KDR (e.g. '--') or use something such as an infinity symbol (e.g. '∞'. That would look pretty 1337. But, you'd probably only want to use that if they had at least one kill.

if ($row['death'] == 0)
{
    if ($row['kill'] == 0) { $kdr = 0; }
    else { $kdr = '∞'; }
}
else
{
    $kdr = $row['kill'] / $row['death'];
}

[Dusaro]

Thanks that fixed it