m****r
发帖数: 202 | 1 29
The following program is submitted to check the variables Xa, Xb, and Xc in
the SASUSER.LOOK data set:
data _null_ WORK.BAD_DATA / view=WORK.BAD_DATA ;
set SASUSER.LOOK(keep=Xa Xb Xc);
length _Check_ $ 10 ;
if Xa=. then _check_=trim(_Check_)!!" Xa" ;
if Xb=. then _check_=trim(_Check_)!!" Xb" ;
if Xc=. then _check_=trim(_Check_)!!" Xc" ;
put Xa= Xb= Xc= _check_= ;
run ;
When is the PUT statement executed?
A.
when the code is submitted
B.
only when the WORK.BAD_DATA view is used
C.
both when the code is submitted and the view is used
D.
never, the use of _null_ in a view is a syntax error
请问答案是B 还是C 呢？谢谢回答 | l**********9
发帖数: 148 | 2 为了保证view的适时性，view总是在被调用的时候才会执行，所以答案是b | m****r
发帖数: 202 | |
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