IBM Assembler Interview Question:

What is the difference in data type "X" and "P"?

Submitted by: Administrator

In MVS assembler data type X denotes hexadecimal data type
which unsigned pack. suppose you define VAR1 as "VAR1 DC
X'01'". It will occupy 1 byte in the memory and stored as:
0 in the zoned nibble and 1 in the numeric nibble.

P denotes the packed data type, similar to COMP-3 in COBOL.
if you declare any variable with this data type then it
must have a sign byte at last nibble. See following example:
VAR2 DC P'1'
it will occupy one byte in the memory and stored as '1C'.
Submitted by: Administrator