topic Re: %qsubstr in SAS Programming

%qsubstr

SAS_inquisitive — Mon, 05 Jun 2017 20:41:49 GMT

I wonder why this does not work.

data _null_;
	a = %qsubstr(12&34,1,4);
	put a;
run;

expected ouput : 12&3

Re: %qsubstr

Astounding — Mon, 05 Jun 2017 20:58:06 GMT

Macro functions are not part of a DATA step. You might as well have coded:

data _null_;
a = 12&34,1,4;
put a;
run;

Note that Kurt is right about what you get when you do use %QSUBSTR ... 12&3 (not what I posted above). Now that will get resolved by as DATA step into the number 1. 12 is true, 3 is true, so 12 & 3 is true and gets resolved to 1.

In a DATA step, you might simply use:

data _null_;
a = substr('12&34',1,4);
put a;
run;

Single quotes always turn off macro processing, whether in a DATA step or in macro language statements.

Re: %qsubstr

Kurt_Bremser — Mon, 05 Jun 2017 20:51:41 GMT

After resolution of the macro function, you get this data step:

data _null_;
  a = 12&3;
  put a;
run;

& is a mnemonic for the boolean "and" operator, so the SAS interpreter sees the 12 and the 3 as boolean values; since both are non-zero, this resolves to the boolean expression "true and true", so the result is "true", which is represented in SAS by 1.

If you wanted a to be the string "12&3", you would have needed to write

data _null_;
  a = "%qsubstr(12&34,1,4)";
  put a;
run;

Re: %qsubstr

SAS_inquisitive — Mon, 05 Jun 2017 21:16:17 GMT

Thank you both for great explanation.