请高手解答,这两个code到底是哪里不一样呢?为什么出来的结果不同呢?
62 %let a =cat;
63 %macro animal (a=frog);
64 %let a=bird;
65 %mend;
66 %animal(a=pig) %put a is &a;
a is cat
67 run;
68
69
70 %let a=cat;
71 %macro animal;
72 %let a=bird;
73 %mend;
74 %animal
75 %put a is &a;
a is bird
76 run;