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

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.

    ISO C truncates towards zero.  It specifically says in 6.5.5
    Multiplicative Operators:

    If the quotient a/b is representable, the expression (a/b)*b
    + a%b shall equal a.

    So -27 % 7 yields -6.

    - Sascha