关于宏变量

现在想定义一个字符串宏变量  varlist 等于  a b c d g


试了一下如下的方法
%let varlist=%str(a,b,c,d,g)


%let varlist=a,b,c,d,g

%put &varlist;

%put &&varlist;



大多有这个提示   该怎么操作啊

ERROR: 检测到开型代码语句的递归。

1 : missing a semicolon
2 : you just try to create a global macro variable, but actually create it outside any macro at all, which is illegal.

hope this will help you.