How can I add a underscore at the end of each macro variable

[bayzid]

How can I add a underscore at the end of each macro variable?

For example, I have: %LET mvar= var1 var2 var2.. I want mvar to contain var1_ var2_ var2_

[Tom]

That is adding underscores in the MIDDLE of the VALUE of the macro variable.

If you know that the string only has one space between the words then you can use TRANWRD() function.  You will have to use the %SYSFUNC() macro function to use TRANWRD() function in macro code.

%let mvar=%sysfunc(tranwrd(&mvar,%str( ),%str(_ )))_;

If you are worried it might have multiple spaces between the words then use COMPBL() first.

%let mvar=%sysfunc(tranwrd(%sysfunc(compbl(&mvar)),%str( ),%str(_ )))_;

Example

818  %LET mvar= var1   var2   var2 ;
819
820  %let mvar=%sysfunc(tranwrd(%sysfunc(compbl(&mvar)),%str( ),%str(_ )))_;
821
822  %put &=mvar;
MVAR=var1_ var2_ var2_

[Ksharp]

 %LET mvar= var1   var2   var2 ;

 %let mvar=%sysfunc(prxchange(s/(\w+)/$1_/,-1,&mvar));

 %put &=mvar;