data two;
y='2';
run;
%let x=10;
%let var=y;
data one;
set two (keep=&var);
z=&var*&x;
run;
which one of the following is the value of the variable Z when the progeam finishes execution?
A.ERROR
B.20(as a numeric)
C.20(as a character)
D. .(missing numeric)
Answer: B
我只晓得macro variable 应该都是character, 但是macro variable进行运算时会自动从character transfer to numeric?
请高手帮忙解读为什么答案是B.3xxxx