RE: Binary variables in RPG

["Joe Pluta" <joepluta@xxxxxxxxxxxxxxxxx>]

> 
> I've recently observed that a 2-byte binary variable that is a field
> within a data structure apparently gets clamped to 4 digits, even
though
> the natural floor and ceiling for a 2-byte signed binary are -32768
and
> +32767.

4B0 is not equivalent to 5I0, which is why there are two different data
types.  Why do it this way?  The closest I can figure is that binary
data types were meant to be simply another form of decimal data, like
packed or zoned.  With decimal numbers, when you add 1 to a four-digit
field containing 9999, you get 0.  Thus the "ceiling" at 9999.  My guess
is the floor is -9999.  That also explains why a 2-byte binary field is
specified as 4B0 - it can hold up to four digits of data.

Conversely, the size of integer field types I and U indicates the number
of bytes in the field.  So if you want integer arithmetic, use the
integer field types, either I or U.  The unfortunately named binary
field type B is pretty much obsolete at this point in time.

Joe