[OCLUG-devel] Limiting range of random numbers

[Tim Thelin]

James Colannino wrote:

> James Colannino wrote:
>
>> Hey everyone,
>>
>> I'm using the following code snippet to generate suedo-random 
>> numbers[...]
>
>
>
> Ok, well, after playing around a bit and trying a few random things, I 
> think I managed to stumble across a possible solution.  If I return 
> (number % 20) instead of just number, it seems to always give me a 
> value between 0 and 19.  I'm not quite sure why this works (if someone 
> could tell me how that would be great) but hey, at least it's working :)
>
> James

That's because x % y is modulo math.  The expression returns the 
remainder of x / y.

So
4 % 2 == 0
5 % 2 == 1
6 % 2 == 0

9 % 3 == 0
11 % 3 == 2

And any number X in the expression X % 20 will yield a number between 0 
and 19.

Tim