Re: [PHP-DEV] Re: #22527 [Opn->Bgs]: Modulus returned negative value

Well, Perl can lean the other way as well actually.  Try this:

  use integer;
  print -27%7;

You will see it gives you -6.  Like I said, it comes down to which way you 
truncate.  Programmers tend to think that something like (int)(-3.4) 
should result in -3.  If that is what you expect, then I think you also 
have to expect -27%7 to return -6.  

-Rasmus

On Tue, 4 Mar 2003, George Schlossnagle wrote:

> Interesting.
> 
> I don't know what the ISO standard say, but mathematically a a % b will 
> always return you an integer 0 <= a%b < b (since there are no negative 
> numbers in canonical representation of Z/bZ).  I guess perl/python/tcl 
> ddecided to adhere to the mathematical definition.
> 
> 
> On Tuesday, March 4, 2003, at 02:37  AM, Rasmus Lerdorf wrote:
> 
> > This is actually an interesting question.  Should we be truncating 
> > towards
> > zero?  I'd say yes, but then I tested Perl, Python and Tcl, and they 
> > all
> > say that -27 % 7 is 1 which means they truncate towards negative 
> > infinity.
> 
> 
>