COMPRESS Function Modifier Warning

[djbateman]

Can someone explain to me why I'm getting the warning that I'm getting?  I've tried reading other posts and can't find a solution.

At various times throughout a program, I am passing a parameter that is typically 2-6 characters plus a 3-digit number through a macro.  In the macro, I am trying to extract just the digits.  I'm trying to use the A modifier in the compress() function, but I get a warning that appears twice with every pass of the macro:

WARNING: In a call to the COMPRESS function or routine, the modifier "'" not valid.

The warning isn't influencing the output (as you can see in the log), but I still want to understand the warning:

6968   %macro check (dsin=);
6969       %let checkval=%sysfunc(compress(&dsin.,'','a'));
6970       %put CHECKVAL=~~~&checkval.~~~;
6971   %mend check;
6972
6973
6974   %check (dsin=AE001);
WARNING: In a call to the COMPRESS function or routine, the modifier "'" not valid.
WARNING: In a call to the COMPRESS function or routine, the modifier "'" not valid.
CHECKVAL=~~~001~~~

Here is a very small portion of the macro I am running with various test cases for the input parameter:

%macro check (dsin=);
	%let checkval=%sysfunc(compress(&dsin.,'','a'));
	%put CHECKVAL=~~~&checkval.~~~;
%mend check;

%check (dsin=AE001);
%check (dsin=AE002);
%check (dsin=AE003);
%check (dsin=AE004);
%check (dsin=AE005);
%check (dsin=CFAE003);
%check (dsin=AE003);
%check (dsin=AE004);
%check (dsin=AE011);
%check (dsin=BF012);
%check (dsin=ZQ014);
%check (dsin=LKNM016);

[novinosrin]

syntax check

Try-

6968   %macro check (dsin=);
6969       %let checkval=%sysfunc(compress(&dsin.,  ,a));
6970       %put CHECKVAL=~~~&checkval.~~~;
6971   %mend check;
6972
6973
6974   %check (dsin=AE001);

[novinosrin · Accepted solution]

This works for me

%macro check (dsin=);
	%let checkval=%sysfunc(compress(&dsin,,ai));
	%put CHECKVAL=~~~&checkval.~~~;
%mend check;

%check (dsin=AE001)

I added i modifier to your a to ignore case sensitive operation 

[xinzhou]

This solutions works for me

[djbateman]

Oh my goodness.  It was just the single quotes around the A modifier?  I was trying so many different things like quotes around the &dsin. parameter or quotes around blank space in the 2nd compress parameter.  Nothing was working, but removing the quotes around the modifier did the trick.  Thanks!

[Sukesh33]

@djbateman, Thanks! it helped me resolve the same warning.