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question regarding % operator.

Tim Rentsch
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Eric Sosman <(E-Mail Removed)> writes:

> On 3/12/2012 10:02 AM, somenath wrote:
>> Many thanks for the great response.
>> So in case of 7/3 there also exist choices. It can be either 2 or 3.
>> But in C it is 2. So does it mean the choice was made to round toward
>> zero?

> Yes, even before C was standardized. The original K&R (now
> sometimes called "K&R I" to distinguish it from the later work)
> says
> When positive integers are divided truncation is toward
> zero, but the form of truncation is machine-dependent if
> either operand is negative. [...] It is always true
> that (a/b)*b + a%b is equal to a (if b is not 0).
> This particular choice was made for C in Ancient Times. One
> supposes that it was inspired by the behavior of the machines
> known to R, and that the leeway for negatives represented R's
> caution about machines where C might someday be implemented.
> The freedom was preserved in the original ANSI Standard, but
> by the time C99 rolled around the Committee apparently decided
> that "round toward minus infinity" machines were either non-
> existent or so rare as to be negligible.

I believe there was also some pressure to converge
on a single definition that would conform to other
standard languages, regardless of whether those
machines were negligibly rare or not.
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