expression is
a
type
The is a
operator evaluates to true
if the given value can be converted to the given type. If the given value cannot be converted to the given type, the is a
operator evaluates to false
.
In HyperTalk, you can only use is a
to test if some value is an integer
, a number
, a date
, a point
, or a rectangle
. However, the test for a date
will accept just about any string to the point of being nearly useless, and the tests for point
and rectangle
are broken: if the value is not a comma-delimited list of integers, the expression will trigger an "Expected integer here" script error instead of evaluating to false
. XION will only consider something a date
if it can actually be converted to one, and will never trigger a script error when evaluating the is a
operator.