Re: [xsl] XPath MOD 10 calculation

["Andrew Welch" <andrew.j.welch@xxxxxxxxx>]

On 5/25/07, David Carlisle <davidc@xxxxxxxxx> wrote:
> Note you only need to do that if calculating the check digit, (when it
> matters that you get 0 not 10) if you are just checking that a given
> checksum is right then you don't need that complication as using 10 or 0
> is the same in a (..) mod 10 = 0 test.
>
> If you a_re_ calculating the digit, rather than write
> (10 - (foo mod 10)) mod 10
> it's probably more natural just to use
> -(-foo mod 10)

Out of interest, why is:

-(-foo mod 10)

not the same as:

foo mod 10

?