views:

322

answers:

9

Perhaps this is the wrong sort of question to ask here but I am curious. I know that many languages will simply explode and fail when asked to divide by 0, but are there any programming languages that can intelligently handle this impossible sum - and if so, what do they do? Do they keep processing, treating 350/0 as 350, or stop execution, or what?

A: 

i'd be surprised if any language returns 350 if you do 350/0. Just two examples, but Java throws an Exception that can be caught. C/C++ just crashes (i think it throws a Signal that can probably be caught).

mlathe
There are two distinct languages called C and C++, and I don't think either of them has any specific provision in their standards. Some implementations of one or both languages may well throw signals.
David Thornley
+1  A: 

In Java, division by zero in a floating-point context produces the special value Double.POSITIVE_INFINITY or Double.NEGATIVE_INFINITY.

mobrule
or `Double.NaN`, if you divide zero by zero.
mobrule
+3  A: 

The little-known Java programming language gives the special constant Double.POSITIVE_INFINITY or Double.NEGATIVE_INFINITY (depending on the numerator) when you divide by zero in an IEEE floating-point context. Integer division by zero is undefined, and results in an ArithmeticException being thrown, which is quite different from your scenario of "explosion and failure".

Jonathan Feinberg
How do you double infinity? Doesn't that just give you infinity? Moronic minds want to know!
T.E.D.
Also, if you double not-a-number, does that make it a number?
Jonathan Feinberg
Double is the class holding the NAN constant - moron
mP
@T.E.D Actually, some infinities are bigger than others because of the rate at which they are expanding, eg. SUM(1..n) is a smaller infinity than SUM(1^2...n^2), as n approaches infinity (it's to do with limits in mathematics)
Tony Breyal
A: 

In Delphi, it either throw a compile-time error (if divided by a 0 value const) or a catchable runtime error if it happens at runtime.

It's the same for C and C++.

In PHP you will get a warning:

Warning: Division by zero in <file.php> on line X

So, in PHP, for something like:

$i = 123 / 0;

$i will be set to nothing. BUT $i is not === NULL and isset($i) returns true and is_string($i) returns false.

AlexV
if you only get a warning, what does the expression return?
Peter Recore
Updated answer with more info.
AlexV
+1  A: 

The INTERCAL standard library returns #0 on divide by zero

msw
A: 

From Wikipedia:

The infinities of the extended real number line can be represented in IEEE floating point datatypes, just like ordinary floating point values like 1, 1.5 etc. They are not error values in any way, though they are often (but not always, as it depends on the rounding) used as replacement values when there is an overflow. Upon a divide by zero exception, a positive or negative infinity is returned as an exact result.

Brendan Long
A: 

Python (at least version 2, I don't have 3) throws a ZeroDivisionError, which can be caught.

num = 42
try:
    for divisor in (1,0):
        ans = num / divisor
        print ans
except ZeroDivisionError:
    print "Trying to divide by 0!"

prints out:

42
Trying to divide by 0!
GreenMatt
Version 3.1 still raises a ZeroDivisionError.
dan04
A: 

Floating point numbers as per the IEEE define constants NaN etc. Any continued operation involving thst value will remain unchanged until the end. Integer or whole numbers are different with exceptions being thrown...In java...

mP