Tag: ARRAY

SAS Base (49)

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The following SAS program is submitted:

data WORK.TOTALSALES(keep=MonthSales{12});
set WORK.MONTHLYSALES(keep=Year Product Sales);
array MonthSales{12};
do i=1 to 12;
MonthSales{i}=Sales;
end;
drop i;
run;

The program fails execution due to syntax errors.
What is the cause of the syntax error?
A. An array cannot be referenced on a keep= data set option.
B. The keep= data set option should be (keep=MonthSales*).
C. The keep= data set option should be the statement KEEP MonthSales{12}.
D. The variable MonthSales does not exist.

Check Answer
Answer:  A

注解：KEEP和DROP的对象不能是数组，只能是变量。如果希望去掉数组中的变量，可以直接引用该变量的名字。例如题目中，希望仅保留数组中第12个元素，即MonthSales{12}，可以使用以下KEEP option: KEEP = MonthSales12，如果想保留整个数组：KEEP = MonthSales1 – MonthSales12。

SAS Base (39)

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The following SAS program is submitted:

data WORK.AUTHORS;
array Favorites{3} $ 8 (‘Shakespeare’,’Hemingway’,’McCaffrey’);
run;

What is the value of the second variable in the dataset WORK.AUTHORS?
A. Hemingway
B. Hemingwa
C. ‘ ‘ (a missing value)
D. The program contains errors. No variables are created.

Check Answer
Answer: B

注解：ARRAY statement中，Favorites为数组名字，{3}表示数组中有3个元素，$表示数组中的元素为字符型，8表示数组内的值最长为8个字节，(‘Shakespeare’,’Hemingway’,’McCaffrey’)设定数组元素的初始值。第二个数组元素，即 Favorites{2}，得到的初始值为’Hemingway’，但由于定义了最长8个字符，所以其值为Hemingwa。

SAS Base (13)

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The following SAS program is submitted:

data WORK.TEST;
set WORK.MEASLES(keep=Janpt Febpt Marpt);
array Diff{3} Difcount1-Difcount3;
array Patients{3} Janpt Febpt Marpt;
run;

What new variables are created?
A. Difcount1, Difcount2 and Difcount3
B. Diff1, Diff2 and Diff3
C. Janpt, Febpt, and Marpt
D. Patients1, Patients2 and Patients3

Check Answer
Answer: A

注解：ARRAY statement用于定义Array内的元素。题目中，Janpt, Febpt和Marpt是来自于Measles data set的旧变量，仅有Difcount1, Difcount2和Difcount3是新建立的变量。