Best SAS Interview Questions and Answers for Job Preparation
Tejasvee Sharma
Jan 23, 2022
Here we have given the list of 45 top SAS Interview Questions for freshers and experienced candidates to practice. These are the questions that are often asked in interviews related to the Statistical Analysis System topic so if you are appearing for a technical job interview then you are advised to go through all the SAS Interview Questions and answers given here.
About SAS: Statistical Analysis System (SAS) is a statistical software suite created by SAS Institute for advanced analytics, data management, business intelligence, multivariate analysis, predictive analytics, and criminal investigation. SAS was invented at North Carolina State University when SAS Institute was included.
SAS stands for Statistical Analysis System, which is an integrated collection of software products.
Writing reports and graphics
Data Warehousing
Information retrieval and data management
Statistical analytics, econometrics, and data mining
Business planning, forecasting, and decision support
Operation Research and Project management
Application Development
Improve Quality
2. Tell the primary structure of the SAS base program?
The primary structure of SAS includes of
==DATA step, which retrieves & manipulates data.
==PROC step, which interprets the data.
3. Explain SAS basic syntax style?
To execute the program successfully, you need to follow these basic elements:
At the end of every line, there should be a semi-colon.
A data statement that describes your data set
Input statement
Each word or statement at least have one space between
A run statement
For example: In file ‘H: \StatHW\yourfilename.dat’;
4. What do you understand by data step in SAS?
The Data step makes a SAS dataset that takes the data along with a “data dictionary.” The data dicte33ionary contains information regarding the variables and their properties.
5. Tell me the use of the %include statement?
%INCLUDE statement reads a complete file into the existing SAS program you are operating and submits that file to the SAS System instantly.
6. Name the data types of SAS?
Numeric and Character are the data types in SAS.
7. Name the statement that does not execute automatic conversions in comparisons?
“where” statement in SAS does not execute automatic conversions in comparisons.
8. Name the method to debug and test your SAS program?
By using Obs=0 and systems options to trace the code performance in the log you can debug and test your SAS program.
9. Differentiate between nodupkey and nodup?
NODUPKEY compares only BY variables whereas NODUP compares all the variables in our dataset.
10. Name SAS validation tools?
For DataSet: Data set name/ debug Data set: Name/stmtchk
For SAS Macros variables: Options: mprint mlogic symbolgen
11. Tell me the command used to find missing values?
missing_values=MISSING(field1,field2,field3);
12. Tell the function of Proc summary?
It calculates descriptive statistics on numeric variables in the SAS dataset. The syntax of proc summary is similar to that of proc means.
13. What does Proc glm do?
Proc glm executes simple and multiple regression, analysis of covariance, analysis of variance (ANOVAL), multivariate analysis of variance, and repetitive measure analysis of variance.
14. Explain SAS informats?
SAS INFORMATS allows the SAS to read, or input data from external files also called Flat Files ASCII files, sequential files, or text files. The informat also tells SAS how to read data into SAS variables.
15. SAS Informats are placed in what types of categories?
SAS Informats are placed in these three categories:
Character Informats: $INFORMATw
Numeric Informats: INFORMAT w.d
Date/Time Informats: INFORMAT w.
16. What does CATX syntax do?
CATX syntax connects character strings, eliminates trailing and leading blanks, and inserts separators.
17. Tell me the use of PROC gplot?
PROC gplot has more additional options and can form more colorful and fancier graphics.
18. Explain PROC in SAS?
In SAS, PROC steps examine and process data in the formation of a SAS data set. It manages a library of routines that execute tasks on SAS data set options like sorting, listing, and summarizing.
19. Describe the SAS data set?
A SAS data set contains two parts.
A descriptor portion
A data portion
20. Tell me some key concepts of SAS
Key concepts of SAS contains,
SORT procedure
KEEP=, DROP= dataset options
Missing values
Reset to missing, or the RETAIN statement
Data step logic
IN= dataset option
Log
Data types
FORMAT procedure for creating value formats
21. Differentiate between INPUT and INFILE?
INFILE statement basically identifies an external file whereas INPUT statement describe your variables
22. Differentiate between INFORMAT and FORMAT?
INFORMAT: To tell SAS that a number needs to be read in a particular format
FORMAT: To tell SAS how to print the variables
23. Explain factor analysis?
Factor analysis is a general term used for a family of statistical methods associated with the lowering of a collection of observable variables in terms of a small number of latent factors. The primary objective of factor analysis is reducing data and summarization.
24. How to read the variables that you require?
Use input statements with column /line pointers, informats, and length specifiers to read the variables you need.
25. Name the special input delimiters used in SAS?
DLM and DSD are the special input delimiters used in SAS.
26. How does SAS behave towards DSD delimiters?
When you determine DSD, SAS takes two consecutive delimiters as a lost value and eliminates quotation marks from character values.
27. Name the good SAS programming practices for processing big data sets?
The good SAS programming practice for processing big data sets is to sort them in one time using firstobs= and obs=.
28. Tell me the way to exclude or include specific variables in a data set?
By using use DROP, KEEP Statements, and Data set Options you can exclude or include specific variables in a data set.
29. In SAS, how SUBSTR function works?
The SUBSTR function helps in abstracting substring from a character variable.
30. What SAS features helps in checking errors and data validation?
For checking errors the Log can help, and for data validation Proc Freq, Proc Means helps, and sometimes Proc print to view how data looks.
31. Name the ways to do a “table lookup”?
Five ways to do a “table lookup” are:
Format Tables
PROC SQL
Arrays
Match Merging
Direct Access
32. Which statements are used to generate test data with no input data?
By using “put” statement and “Data Null” you can generate test data with no input data.
33. Differentiate CEIL and FLOOR functions in SAS?
The “floor” returns the biggest integer less than or equal to the argument. and the “ceil” function returns the smallest integer greater than or equal to the argument.
34. Differentiate between SAS procedures and functions?
The main difference between SAS procedures and functions is that
Procedures expect one variable value per observation
Functions expect values to be delivered across an observation
35. How to eliminate duplicates using PROC SQL?
To eliminate duplicates using PROC SQL use the following steps:
Proc SQL noprint;
Create Table inter.merged1 as
Select distinct * from inter.readin ;
Quit;
36. What are general programming errors in SAS?
Some general programming errors that happen in SAS are,
Not using Fsview option vigorously
Not checking log after submitting program
Missing semicolon
Not using debugging techniques
37. How to limit decimal places for the variable?
By using MAXDEC=option, you can limit decimal places for the variable.
38. Differentiate between the SAS PROCs and SAS DATA STEP?
SAS DATA STEP is utilized to read in and manage data
SAS PROCs are sub-routines that execute tasks on SAS data set
39. Tell me the use of the STOP statement?
A STOP statement helps you to control the constant looping in the SET statement.
40. Explain RUN-Group processing?
RUN-Group processing permits submitting a PROC step operating the RUN statement without completing the procedure.
41. Tell me the way to test the debugging in SAS?
Use the Debug clause after ‘/’ in the data statement for debugging in SAS.
42. How to make a permanent SAS data set?
There are two necessary steps to make a permanent SAS data set:
Assign a library and engine.
Make the data. Make sure to allocate both a library (other than WORK) and data set name to create the data set permanent.
43. Explain the scrubbing procedures in SAS?
These are the Proc Sort with nodupkey option. It will eliminate duplicate values.
44. Name the default statistics that PROC MEANS produce?
N
MIN
MAX
MEAN
STD DEV
45. Differentiate between Match Merge and One to One Merge?
A one-to-one merge is suitable if both data sets in the merge statement are sorted by id, and each statement in one data set has a corresponding observation in the different data set. If the observations do not match, then match merging is appropriate.
