The ABS function can be used to return a positive value...
DATA POSITIVE_INTEGER;
VALUE = abs(-789);
RUN;
PROC PRINT;RUN;
The SUMABS function is also available, and computes the sum of the absolute value of the non-missing arguments. This example returns a value of 14.
DATA POSITIVE_INTEGER;
VALUE = sumabs(-1, 3, 0, ., -10);
RUN;
PROC PRINT;RUN;
You can also use the OF variable range syntax to include all variables that match a pattern.
data _null_;
x1=1;
x2=3;
x3=4;
x4=3;
x5=1;
x=sumabs(of x1-x5);
put x=;
run;
Thanks to Ayetullah for sharing this tip on sasCommunity.org.