03-20-2013 09:10 AM
I'm trying to figure out why this macro logic is working in this way:
%if 0 lt &bwgt and &bwgt lt 50 %then %put test1;
%if 0 lt &bwgt lt 50 %then %put test2;
This returns test2.
Why is it returning this when bwgt=50?
Obviously I can just write my code with an "and" and get around this issue, but I'm curious as to why this is happening
03-20-2013 09:27 AM
Unlike a DATA step, macro language does not process this as two separate comparisons:
0 lt &bwgt lt 50
Instead, macro language processes from left to right, as if you had coded:
(0 lt &bwgt) lt 50
Like a DATA step, macro language replaces true comparisons with a 0 and false comparisons with a 1. Since both 0 and 1 are less than 50, you will always get "test2" for any numeric value of &bwgt even if it's 55.
Good job on prodding, exploring, and asking.
03-20-2013 09:41 AM
Can't fins any references in documentation to that you can use the same between and logic with %if (as you can with if in the data step). But I can't explain why this is happening. You wanted this test to come up as false, right?