On Aug 19, 2013, at 3:17 PM, Mike Duigou <mike.dui...@oracle.com> wrote:
> - documentation of "bound" should mention that it is exclusive rather than
> relying on the return documentation.
Agreed.
> - I find disallowing the zero bounds and empty ranges slightly annoying. It
> requires me to externally special case for situations such as:
>
> Random ran = new Random();
> String[] users = {"Fred"};
>
> someUser = users[mine.nextInt(users.length - 1)];
>
> This is a frequently used idiom. Yes, forcing the random number generator to
> return zero is silly but for symmetry it is convenient. An empty range isn't
> an obvious error (though the "String[] users = {};" case is obviously an
> error).
But I am puzzled here. Is it really a frequently used idiom to want to set
"someUser" to any element of the array "users" EXCEPT the last one? Because
that is what is asked for by
someUser = users[mine.nextInt(users.length - 1)];
If you want a free choice among ALL elements in the (non-empty) array, then
someUser = users[mine.nextInt(users.length)];
is what you want; and if the array is empty, then you'll get an exception from
the nextInt method rather than the array indexing step, but that amounts to the
same thing: an inability to pick an element from an empty array.
--Guy
