convert char to num and back to char

[thelearner]

D scsw S 2 INZ('03')
D num S 2 0

num = %uns(scsw) -1;
scsw = %editc(num:'X'); // scsw = '02'
why the above coding works but the below doesn't?
scsw = %editc((%uns(scsw)-1):'X'); // scsw = '00'
Is there anyway I can combine the coding into 1 line?

Thanks.

 

[arrow483]

scsw = %editc((%uns(scsw)-1):'X');

The interim work field is a length of 2 bytes, thus has value of 002. If you move it to a char field with editcode of x, you get only the first 2 chars. To test, define a work field:
D Work 10A
Work = %editc((%uns(scsw)-1):'X');

and see what happens. Vary the length of scsw and see the result vary.

You could prob get it in one stmt with %subst, but it would be a lot simpler to leave it as 2 statements.