%macro test( VarX, M_VarY);
/* VarX is a normal macro variable, so itis passed by
value. */
/* Modify the value of VarX */
%let VarX=Customer_Income;
%put ********** Inside the macro test**************;
%put VarX=&VarX;
/* M_VarY is initialized as null and willbe changed
here to return the value "Scorecard". */
%put Initial value of M_VarY=&M_VarY;
%let &M_VarY=Scorecard;
%put ********* Leaving macro test******************;
%mend;
/* Using the macro test */
/* switch off the code echo */
option nosource;
%let VarX=Customer_Age; /* value of varX */
%let VarY=; /* initializing VarY to a null string */
/* display the values before calling themacro */
%put ******** before calling the macro ************;
%put VarX=&VarX;
%put VarY=&VarY;
%test(&VarX, VarY); /* Note that VarY is used without & */
/* display the values after executing themacro */
%put ******** after executing the macro ***********;
%put VarX=&VarX;
%put VarY=&VarY;
关于M_定义的宏参数,在其中的红字行,为什么在M_VarY=Scorecard前面用一个&?
请问有没有教材具体介绍这个的,《SAS统计分析使用宝典》《The Little SAS Book》这两本书都没有介绍这个问题。