对于数组，有一个point是Arrays exist only for the duration of the DATA step. They do not become part of the output data set.
然后有这样一道题：
The following program is submitted:
data work.test;
    array diff_sales{};
run;
问：Which of the variables are written to the Work. Test data set?
既然说是不成为output data set的一部分，为什么题目会问到Work. Test这个data set中有几个变量呢？
还是说最上面的陈述部分意思是指数组不在output data set中，但是其创建的新变量会存入？
求解求解~~~