Commonly Asked SAS Interview Questions with Answer : 76 - 80

Ques 76 : What is the difference between file extension .SAS and .LST in SAS ?

Ans : File extension is an identifier for type of file. There are several types of file extensions for SAS files. I am just specifying some of them.

1. x.SAS                  :  SAS Program file
2. x.CFG                 : SAS Configuration file
3. x.LST                  : SAS Output file
4. x.LOG                 : SAS Log file
5. x.SAS7BPGM    : SAS Stored Program file
6. x.SAS7BDAT     : SAS Data Set file
7. x.SAS7BVEW    : SAS Data Set View file
8. x.SAS7BCAT     : SAS Catalog file
9. x.SAS7BUTL     : SAS Utility file
10. x.SAS7BNDX    : SAS Data Set Index file

• x is a name of file

Ques 77 : What is the default action of Frequency Procedure (Proc Freq) ?

Ans :  The default action of Frequency Procedure is to calculate frequencies on each variable irrespective of character or numeric of defined SAS data set.  

It means we can use PROC FREQ to compute frequencies for both character and numeric variables.

By default Proc Freq calculates four statistics on each variable which are Frequency, Percent, Cumulative Frequency and Cumulative Percent.

• Proc Freq is not only a descriptive procedure as well as a statistical procedure which produces one way and n-way frequency tables

Ques 78 : How to get the output in List format rather than as a Cross Tabulation in Proc Freq ?

Ans : We can specify LIST option in Proc Freq to print the table in list format.

Ques 79 : How do we get to know that which SAS products are licensed and Installed at our machine ?

Ans : We can use Setinit Procedure (Proc Setinit) to get to know about licensed SAS products for our machine. 

Most of the time, we may have some SAS products licensed but not installed so to get to know only installed products we can use Product_Status Procedure (Proc Product_status).

Syntax : 

Ques 80 : How could we count the number of missing values of numeric variable in SAS ?

Ans : We can count the number of missing values for numeric variables by using NMISS option in PROC MEANS. 

Proc Means requires at least one numeric variable to calculate statistics.

Syntax :