The use of 'array[boolean]' does not mean that the array is true or false,
but rather '0..1'. You indicate a range, not a boolean behavior.
6 and 4 gives 4, and 4 is above the range of 1 (the highest cell of the
array you declared). If you would have cast it to boolean, or provide a
better usage,
On Fri 23 Oct 2009, ik wrote:
The use of 'array[boolean]' does not mean that the array is true or
false, but rather '0..1'. You indicate a range, not a boolean
behavior.
Well, pascal is a typed language, so while I do realize that the
information is stored as false=0 and true=1, and that's
David Emerson wrote:
I did cast it to boolean! That's why it smells like a bug
var
b : boolean;
begin
b := boolean (6 and 4);
writeln (t_or_f [b]);
A type cast does not changes the value. A typecast merely allows you to
store a value into a field of a different type
same for
Thanks, Martin -- I'm doing the if/then, and am being reminded of what
typecasting actually does!
On Fri 23 Oct 2009, Martin wrote:
A type cast does not changes the value. A typecast merely allows you
to store a value into a field of a different type
It appears that, in a special case here, the boolean typecast is not
being done properly/completely, and thus an array is being indexed out
of bounds. If I compile with rangechecking, I get a rangecheck error;
without, I get garbage and an EAccessError exception! (trash and crash)
uses math;
