Division by zero error?

Question

If I get a division by zero, how can I catch it and just echo an error or something of that nature?

Here's the line of code in question:

$percent = round(100.0*($row['p2']/$row['p1']-1));

well division by zero is infinite so you must check its not zero — NullPoiиteя, Aug 11 '13 at 06:23

score 1 · Answer 1 · answered Aug 11 '13 at 06:27

1

Just check that $row['p1'] is not zero.

If it is zero do something else (e.g. report an error)

answered Aug 11 '13 at 06:27

Ed Heal

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Hubro · Accepted Answer · 2013-08-11T06:36:38.480

-1

Division by zero in PHP returns false and displays a warning message. You can squelch the warning message by appending @ to the expression in question.

$foo = @(10 / 0);

if ($foo === false) {
   // Division by zero
}

It would be cleaner to just try to avoid dividing by zero in the first place though.

Suppressing warning messages is usually a sign that you should be doing something differently. For instance, simply check if the integer is 0 before using it for division.

edited Aug 11 '13 at 06:36

answered Aug 11 '13 at 06:28

Hubro

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pretty bad method ... why not check that weather divisor is zero or not – NullPoiиteя Aug 11 '13 at 06:33
@NullPoiиteя: I answered the question and advised the OP to use a better method. Why on earth down vote that? – Hubro Aug 11 '13 at 06:34
i didnt down vote ... – NullPoiиteя Aug 11 '13 at 06:34
Why not make it apparent by doing `if ($var == 0)` instead of suppressing warning? – vee Aug 11 '13 at 06:34
2

IMO error suppression operator is for experts only. It's bad to abuse it. – Wesley Murch Aug 11 '13 at 06:34
@WesleyMurch TRUE ..new bie abuse it and use it like magic error removing thing – NullPoiиteя Aug 11 '13 at 06:37
1

IMHO - Do not use the error suppression operator at all. Errors are there for a reason. – Ed Heal Aug 11 '13 at 06:37
@EdHeal: Why have a warning suppression mechanism if there are no warnings worth suppressing? – Hubro Aug 11 '13 at 06:38
@Codemonkey there are plenty of thing PHP has but we do not use ... and its php so useless function and operator can exist :) – NullPoiиteя Aug 11 '13 at 06:42
@Codemonkey - It is there for the lazy. – Ed Heal Aug 11 '13 at 06:45
3

*Don't suppress errors, fix them!* – Amal Murali Aug 11 '13 at 07:07
@AmalMurali: It's not like I'm recommending it in my answer. I'm simply answering what the OP asked, then recommending **not** doing it :) – Hubro Aug 11 '13 at 07:10
Thanks @Codemonkey - large excel sheets are being imported & compared so sometimes dividing by zero may occur if the numbers are the same (Comparing data between two months.) – Alex Aug 11 '13 at 18:19

score -2 · Answer 3 · answered Aug 11 '13 at 06:34

-2

If value of $row['p1'] is 0, then you will get division by zero error. If you want to catch it without showing ugly Exception in the UI, you can write like this.

try {
    $percent = round(100.0*($row['p2']/$row['p1']-1));
} catch() {
    echo 'Caught exception: ',  $e->getMessage(), "\n";
}

You will get the exact error message now. And better to use the condition if(0 !== $row['p1']).

answered Aug 11 '13 at 06:34

prava

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neither i see any need of try cache .. so bad(*) method too – NullPoiиteя Aug 11 '13 at 06:35
division by zero doesn't throw exception. http://ideone.com/HHkkEq – RiaD Aug 11 '13 at 07:02

Division by zero error?

3 Answers3