topic How can I make a global macro var in %macro? in New SAS User

How can I make a global macro var in %macro?

braam — Thu, 03 Oct 2019 16:23:02 GMT

I used %let to define local macro in %macro statement, but it was gone way outside of the macro. Because I would like to use macro variables generated in %macro outside of it, I want to use global macro. But, replacing %global with %let doesn't work for me. Do they work differently?

Relatedly, can I simply re-define local macro variables to global macro ones?

Re: How can I make a global macro var in %macro?

Quentin — Thu, 03 Oct 2019 16:39:46 GMT

Hi,

Please show the code you have tried. This will make it easier to explain why it's not working.

It's a good idea to always use the %LOCAL or %GLOBAL statement to explicitly declare the scope of macro variables (there are rare exceptions to this rule).

Yes you can use the %GLOBAL statement in a macro to create a global macro variable, for example:

%macro try() ;
  %global x ;
  %let x=1 ;
%mend try ;

%try()

%put &=x ;

No, if you have a local macro variable, you cannot use the %GLOBAL statement to redefine it as global. The below log shows the error that will be generated if you try:

615  %macro try() ;
616    %local x ;
617    %let x=1 ;
618    %global x ;
619    %let x=1 ;
620  %mend try ;
NOTE: The macro TRY completed compilation without errors.
      15 instructions 236 bytes.
621
622  %try()
ERROR: Attempt to %GLOBAL a name (X) which exists in a local environment.

HTH,

-Q.

Re: How can I make a global macro var in %macro?

Tom — Thu, 03 Oct 2019 16:41:13 GMT

Note that you use %LET to assign values to macro variables, not to create LOCAL or GLOBAL macro variables.

I suspect you are just confused because if the macro variable you are assigning a value to does not already exist then it will be created as LOCAL.

Try this

%macro mymacro;

%if not %symexist(mymvar) then %global mymvar;
%let mymvar=Hi there;

%mend mymacro;


%mymacro;
%put My Macro Varaible = &mymvar;