BIS524 Chapter 1

How do you decide?
Back to the question. Consider these two comparisons.

Numeric variables are stored in 8 bytes while
Character variables are stored with as many places as you require (between 1 and 200 bytes).
You can do arithmetic on a numeric variable while
Character variables and arithmetic do not work well.

Deciding
On the first count, it would seem to be better to define TYPE as a single-character variable.

   INPUT @20 TYPE $1. @;

On the other hand, it would seem to be better to define SSN as numeric since the following code will use 9 bytes of storage to record the social security number.

   INPUT @20 SSN $9. @;  
DATALINES;  
...            123456789

On the second count, since you are not doing any arithmetic on TYPE, it would seem to be better to define TYPE as a single-character variable.