求教如何选择字符的某一段

shiyiming

我有一组变量名分别表示road, traffic, inhabitants,但是在末尾有100 300 500的postfix,如road_100,road_300等，现在我想将凡是后缀为100的变量找出来，应该怎么办，其实也就是能否用substr实现倒序的选择字符？我能想到就是用substr和index的联用，不知道对不对？

shiyiming

scan()

shiyiming

substr()

Qiong

data v;
v_100=1;
v_200=2;
s_100=3;
t_100=4;
c_100="a";
c_200="b";
run;

proc contents data=v out=v_temp(keep=name) noprint;
run;

proc sql noprint;
select name into: keepvar separated by " "
from v_temp
where substr(name,length(name)-3,4)="_100";
quit;

%put &keepvar;