SAS Base Programming Specialist Interview Questions

SAS is a fourth-generation programming language (4GL) for data access, analysis, transformation, and reporting. It is built into the SAS Platform. Base SAS is designed for basic data manipulation, descriptive statistics, data storage, and retrieval, and report writing. SAS Base Programming Specialist (A00-231) certification is a SAS program that validates a candidate’s skills and abilities. Therefore, to help you prepare for SAS Base Programming Specialist Interview we have curated expert level questions and answers:

1.. Define SAS.

SAS is the answer (Statistical Analytics System):

Firstly, SAS is a software suite that specializes in advanced analytics, multivariate analyses, business intelligence, data management, and predictive analytics.
SAS Institute is the company that created it.
Netx, SAS provides non-technical users with a graphical point-and-click user interface as well as more advanced options via the SAS language.

2. What are the characteristics of SAS?

SAS has the following characteristics:

Business Solutions: SAS offers business analysis as business products that can be used by a variety of companies.
SAS is the market leader in analytics for a wide range of business products and services.
SAS can also be used as a database management system (DBMS).
Hello SAS aids in the visualisation of analysis in the form of summaries, lists, and graphic reports.
Visualization: The reports can be visualised using graphs ranging from simple scatter plots and bar charts to complex multi-page classification panels.

3. Mention a few SAS Framework capabilities.

SAS Framework has four capabilities, which are as follows:

Access: As shown in the figure, SAS allows us to access data from a variety of sources, including an Excel file, a raw database, an Oracle database, and SAS Datasets.
Manage: We can then manage this data by subsetting it, creating variables, validating and cleaning it.
Analyze: This data is then analysed further. We can run simple analyses like frequency and averages as well as complex ones like regression and forecasting. SAS is widely regarded as the gold standard for statistical analysis.
Finally, we can present our findings in the form of a list, summary, or graphic report. We can print these reports, save them to a data file, or make them available online.

4. In an SAS programme, what is the purpose of the output statement?

To save summary statistics in a SAS data set, use the OUTPUT statement. This data can then be used to generate customize reports or save historical data about a process.

Options in the OUTPUT statement can be used to
Specify which statistics should be saved in the output data set.
Give the output data set a name, and
Compute and save percentiles that are not computed automatically by the CAPABILITY procedure.

5. What is the distinction between reading data from an external file and reading data from a pre-existing data set?

The main difference is that when using the SET statement to read an existing data set, SAS keeps the variable values from one observation to the next. When data is read from an external file, only the observations are read. If the variables are to be used, they must be re-declared.

6. How many data types does SAS support?

In SAS, there are two data types. Characters and numbers Dates are also considered characters, despite the fact that there are implicit functions that work with dates.

7. What does the Stop statement do in an SAS programme?

The stop statement causes SAS to immediately stop processing the current data step and resume processing after the current data step is completed.

8. What is the difference between using the drop = data set option in a data statement and using it in a set statement?

If you do not want certain variables to be processed and do not want them to appear in the new data set, use the drop = data set option in the set statement.If, on the other hand, you want to process specific variables but do not want them to appear in the new data set, use the drop = data set option in the data statement.

9. What’s the distinction between SAS functions and SAS procedures?

In a SAS data set, functions expect argument values to be supplied across observations, whereas procedures expect one variable value per observation.

10. What’s the distinction between PROC MEANS and PROC SUMMARY?

Firstly, PROC MEANS generates subgroup statistics only when a BY statement is used and the input data has been previously sorted by the BY variables (using PROC SORT).

Secondly, PROC SUMMARY generates statistics for all subgroups automatically, providing all the information in a single run that would be obtained by repeatedly sorting a data set by the variables that define each subgroup and running PROC MEANS. PROC SUMMARY does not generate any data in your output. To see the computed statistics, use the OUTPUT statement to create a new DATA SET and PROC PRINT.

11. Give an example of when SAS fails to automatically convert a character value to a numeric value.

Assume the variable PayRate’s value starts with a dollar sign ($). When SAS attempts to automatically convert PayRate values to numeric values, the dollar sign prevents the process from proceeding. The values can’t be converted to numbers. As a result, whenever conversions occur, it is always best to include INPUT and PUT functions in your programs.

12. How does PROC SQL operate in SAS Base Programming?

PROC SQL is a process that runs all of the observations at the same time. When PROC SQL is run, the following events occur:

SAS checks syntax errors, such as missing semicolons and invalid statements, in each statement in the SQL procedure.
The query within the statement is scanned by the SQL optimizer. The SQL Optimizer determines how to execute the SQL query in order to minimise run time.
Any tables specified in the FROM statement are loaded into the data engine and can be accessed in memory.
Code and calculations are carried out.
The Final Table is built in memory.
Final Table is routed to the SQL statement’s output table.

13. When it comes to dates in SAS Base Programming data, how do they work?

Every data set revolves around data. Data in SAS is presented in tabular form, with variables occupying the column space and observations occupying the row space. SAS considers numbers to be numeric data, while everything else is character data. As a result, SAS has two data types: numeric and character. Aside from these, dates in SAS are represented differently than in other languages. Aside from Date Values, there are numerous tools for working with dates, including informants for reading dates, functions for manipulating dates, and formats for printing dates.

14. What’s the distinction between do-while and do until?

The DO WHILE expression is evaluated at the top of the DO loop, which is an important distinction between the DO UNTIL and DO WHILE statements. The DO loop is never executed if the expression is false the first time it is evaluated. DO UNTIL, on the other hand, executes at least once.

15. Can a variable that only contains numbers be a character data type?

Yes, depending on how you use the variable. Some numbers will be used as a categorical value rather than a quantity. A variable called “Foreigner” is an example of this, with the observations having the value “0” or “1” representing not a foreigner and foreigner, respectively. Similarly, the ID of a specific table can be a number but does not explicitly represent any quantity. Another common example is phone numbers.

16. Give some examples of where the defaults of PROC REPORT differ from those of PROC PRINT.

No Record Numbers in Proc Report
Labels (not var names) used as headers in Proc Report
REPORT needs NOWINDOWS option

17. Give some examples of where the defaults of PROC REPORT and PROC PRINT are the same.

Variables/columns are listed in ascending order.
Rows are ordered in the order that they appear in the data set.

18. What is the significance of the @ and @@ trailing characters? How do you put them to use?

The trailing @ symbol is also known as a column pointer. The trailing @ in the Input statement allows you to read a portion of your raw data line, test it, and then decide how to read more data from the same record.

The single @ at the end instructs the SAS system to “hold the line.”
Secondly, the @@ symbol instructs the SAS system to “hold the line more strongly.”
When an Input statement ends with @@, the programme is instructed to release the current raw data line only when there are no more data values to be read from that line. As a result, the @@ retains the input record even after multiple iterations of the data step.

19. What is the distinction between the Order and Group variables in a proc report?

Rows with the same values are collapsed if the variable is used as a group variable.
Group variables generate a list report, whereas order variables generate a summary report.

20. Can you describe some methods for defining variables in order to generate the summary report (using proc report)?

In a summary report, all variables must be defined as group, analysis, across, or computed variables.

21. What is the distinction between a CLASS statement and a BY statement in a proc?

In contrast to CLASS processing, BY processing requires that your data be sorted or indexed in the order of the BY variables. The layout of BY group results differs from that of CLASS group results.

22. What is the distinction between PROC MEANS and PROC Summary?

The difference between the two procedures is that PROC MEANS, by default, generates a report. To generate a report in PROC SUMMARY, however, you must include a PRINT option in the PROC SUMMARY statement.

23. Explain how merging aids in the combination of data sets.

Merging is the process of combining observations from two or more SAS data sets into a single observation in a new data set. A one-to-one merge, as illustrated in the figure below, combines observations based on their position in the data sets. For one-to-one merging, you use the MERGE statement.

24. What exactly is interleaving in SAS Base Programming ?

Interleaving is the process of combining individual, sorted SAS data sets into a single, sorted SAS data set. The figure below depicts the value of the variable used to sort the data sets for each observation. A SET statement and a BY statement are used to interleave data sets.

25. What is the distinction between One to One and Match Merge?

A one-to-one merge is appropriate if both data sets in the merge statement are sorted by id (as shown below) and each observation in one data set has a corresponding observation in the other data set.

26. What are the Scan function’s parameters?

This is how the scan function is employed.

scan(argument,n,delimiters)

Firstly, the argument specifies the character variable or expression to scan in this case.
n indicates which word should be read, and
Delimiters are special characters that must be surrounded by single quotes.

27. What are a few SAS functions?

Scan, Substr, trim, Catx, Index, tranwrd, find Sum.

28. What does the tranwrd function do in SAS Base Programming?

TRANWRD replaces or removes all occurrences of a character pattern within a character string.

29. What would the outcome of the following SAS function be (given that December 31, 2000 is a Sunday)?

Firstly, Weeks = intck (‘week,’31 December 2000’d,’01 January 2001’d);
Months = intck (‘month’,’31 dec 2000’d,’01jan2001’d); Years = intck (‘year’,’31 dec 2000’d,’01jan2001’d);
In this section, we will compute the weeks between December 31st, 2000 and January 1st, 2001. The 31st of December, 2000, was a Sunday. As a result, the 1st of January 2001 will be a Monday in the same week. As a result, Weeks = 0.
Years = 1 because both days fall in different calendar years.
Months = 1 because the two days are in different calendar months.

30. In SAS, how many different data types are there?