topic %eval return an boolean value, how? in SAS Programming

%eval return an boolean value, how?

ZRick — Wed, 04 Apr 2012 16:00:41 GMT

Can anyone give an example of %eval that returns a boolean value, true/false?

In sas help, it says "If at least one operand cannot be interpreted as numeric, the expression is treated as logical."

But it doesn't give an example, I tried following:

%eval('0'+1);

it returned an error

I can't think of one example.

Tom — Wed, 04 Apr 2012 16:06:04 GMT

Use %SYSEVALF if you want to enforce the format of the returned value.

%sysevalf(4+5,boolean) will return 1 instead of 9.

Astounding — Wed, 04 Apr 2012 16:15:16 GMT

You can also simulate the result, using %EVAL. This expression also returns a 1:

%eval ( (4+5) ne 0)

However, %SYSEVALF will also return 0 for calculated missing values. %EVAL returns an error.

Also note that %EVAL is still limited to integer arithmetic. These expressions return different results:

%sysevalf(4/5, boolean)

%eval( (4/5) ne 0)

Hope this helps, rather than confuses the issue!

chang_y_chung_hotmail_com — Thu, 05 Apr 2012 18:03:05 GMT

Here is an example. hth

%put %eval( 1.0 eq 1);
%*-- returns 0 for false -- *;