From SAS HELP: Assigning the results of TRIM to a variable does not affect the length of the receiving variable. If the trimmed value is shorter than the length of the receiving variable, SAS pads the value with new blanks as it assigns it to the variable.
TRIM函数的功能是Removes trailing blanks from a character string,与变量长度无关。
data test;
a=length('Paris '||' Londen');
b=length(trim('Paris ')||trim(' Londen'));
put a=;
put b=;
run;