问两道SASBase题目

40.ThefollowingSASprogramissubmitted:

datawork.pieces;

dowhile(nlt6);

n+1;

end;

run;

WhatisthevalueofthevariableNintheoutputdataset?

A.5

B.6

C.7

D..(missingnumeric)

Answer:B

为什么答案选B?一开始n没有被定义啊,在dowhile里n应该是missing啊.你在n+1的时候才被赋值为0的吧……

48.GiventherawdatafileCALENDAR:

----|----10---|----20---|----30

01012000

ThefollowingSASprogramissubmitted:

datatest;

infile'calendar';

input@1datemmddyy10.;

ifdate='01012000'dthenevent='January1st';

run;

WhatisthevalueoftheEVENTvariable?

A.''(missingcharactervalue)

B..(missingnumericvalue)

C.January1st

D.Theprogramfailstoexecuteduetoerrors.

虽然mmddyy10.的读取长度过长了,但是我在SAS程序上涌datalines的方式试了一下还是能够读取的啊,为什么答案说会有错误?