data products;
product_number=5461;
item='1001';
item_reference=item||'/'||product_number;
run;


which one of the following is the value of the variable item_reference in the output？
a. 1001/5461
b. 1001/         5461  八个空格
c. .(missing)
d. the value can not be determined as the program fails to excute due to errors.


答案是b 解释中说到 在sas里实现也确实如此
item_reference expected character but numerical got，so it automatically change it intocharacter by using best 12，begining form right。

为什么会从右边开始呢？？不明白

还有product_number这些是变脸名嘛？那他都超过8个字符啦~为什么还可以用呢？
对于变量名不能超过8个字符究竟是对哪些呢？？？