What is wrong with Call symput()?

[6656]

Hi, Any one can tell why I could not get my macro variables resolved? Sometimes it worked. Pls see below log. Thanks, Mike

133 %macro aa (_var= xyz0103-xyz0108);
134 DATA varname ;
135 do j=1 to 2;
136 varname=scan( "&_var",j,'-');
137 CALL SYMPUT('tmpvar'||left(j),varname);
138 output;
139 end;
140 RUN;
141 %mend aa;
142 %aa;

NOTE: Numeric values have been converted to character values at the places given by: (Line)Column).
142:99
NOTE: The data set WORK.VARNAME has 2 observations and 2 variables.
NOTE: DATA statement used:
real time 0.02 seconds
cpu time 0.02 seconds


WARNING: Apparent symbolic reference TMPVAR1 not resolved.
WARNING: Apparent symbolic reference TMPVAR2 not resolved.
143 %put tmevar= &tmpvar1 &tmpvar2;
tmevar= &tmpvar1 &tmpvar2

 

[teralearner]

Try this:
DATA _null_;
%macro aa (_var= xyz0103-xyz0108);
do j=1 to 2;
varname=scan( "&_var",j,'-');
CALL SYMPUT('tmpvar'||left(j),varname);
output;
end;
%mend aa;
%aa;
run;
You may want to add a trim function to varname to remove trailling blanks.


SYMPUT puts the macro variable in the most local nonempty symbol table. The first time you run you macro, macro variables are created as local macro variables. %put statement is out of the scope of the macro variable. But when you run your macro the second time, local symbol table is not empty any more. Macro variables are created in the nearest nonempty symbol table, in your case, there is no next level of local macro variable table. Therefore, they are created in the globle macro variable table. That is why your code does not work the first time. It works after the first time.

 

[6656]

Thanks Teralearner, you're right. A macro varible created by SYMPUT()must be used only after RUN statement.