Top 120+ SAS Interview Questions and Answers for 2021

Base SAS is a text-based, basic IDE with an older interface. Enterprise Guide (EG) is a more GUI-like IDE with wizards to assist with writing code for various processes.

With the help of the STD function, the standard deviation will be returned for the nonmissing statements.

This type of term is used to make sure that the data which is process is grouped, indexed or even ordered based depending upon the variables.

No, it must be character data type.

With the Ampersand (&) sign.

When we have a long series of mutually exclusive conditions and the comparison is numeric, we use SELECT construct rather than IF-THEN or IF-THEN-ELSE statement because CPU time is reduced.

Global statements are the one used anywhere in a SAS program and takes effect until it is changed, canceled or SAS session ends.

SYMPUT puts the value from a dataset into a macro variable where as SYMGET gets the value from the macro variable to the dataset.

A SAS program is a sequence of statements executed in order. Every SAS statement ends with a semicolon and the statement can be in upper-or lowercase letters.

SAS means “Statistical Analysis Software”.

• Statements
• Variables
• Dataset

Informat - To tell SAS that a number should be read in a particular format.

Format - To tell SAS how to print the variables.

When a data set is closed, its tape positioning is defined by FILECLOSE.

By using MAXDEC= option.

Linear regression is a statistical technique where the score of a variable Y is predicted from the score of a second variable X. X is referred to as the predictor variable and Y as the criterion variable.

Compile

Data Step MERGE does not create a cartesian product incase of a many-to-many relationship. Whereas, Proc SQL produces a cartesian product.

The prime aim of CALENDAR is to make the data of the calendar on monthly basis be visible in the format of the SAS data set.

We can use ‘do until’ or ‘do while’ to specify the condition.

There are two data types in SAS. Character and Numeric. Apart from this, dates are also considered as characters although there are implicit functions to work upon dates.

WHERE statement can sets the criteria for any data set in a data step or a proc step.

The difference between the two procedures is that PROC MEANS produces a report by default. By contrast, to produce a report in PROC SUMMARY, you must include a PRINT option in the PROC SUMMARY statement.

PROC GPLOT identifies the data set that contains the plot variables. It has more options and, therefore, can create more colorful and fancier graphics.

By using $BASE64X encoding, the character data is converted into ASCII text.

Program Data Vector (PDV) is the area of memory where data sets are created through the SAS system, one at a time. When a program is executed, an Input Buffer is created that reads data values and makes them assigned to their respective variables.

Use LIBNAME statement to redirect SAS user folder.

• _N_ is a data counter variables used to indicate the number of times that SAS has looped through the data step.
• _ERROR_ is a implicit variable created by SAS during data processing. It gives the total number of records SAS has iterated in a dataset.

% Local is a macro variable defined inside a macro. %Global is a macro variable defined in open code (outside the macro or can use anywhere).

The character or numeric variables that are specified can be assigned missing values through the CALL MISSING routine.

CALL PRXCHANGE routine helps to perform the pattern matching replacement.

• The single trailing @ tells the SAS system to “hold the line”.
• The double trailing @@ tells the SAS system to “hold the line more strongly”.

You can use PROC SQL with COUNT(DISTINCT variable_name) to determine the number of unique values for a column.

An important difference between the DO UNTIL and DO WHILE statements is that the DO WHILE expression is evaluated at the top of the DO loop. If the expression is false the first time it is evaluated, then the DO loop never executes. Whereas DO UNTIL executes at least once.

No. In order to subset data when grouping is in effect, the HAVING clause must be used. The variable specified in having clause must contain summary statistics.

It is used for assigning an ALTER password, which will stop users from changing the file.

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

By using TABLES Statement.

Select, From, Where, Group By, Having, Order.

Options, title, footnote

It is all about adding at the end so that in case of SAS, there can be one more SAS data which you can add and further more other data set can automatically be added.

ODS stands for the Output Delivery System.

We can read the last observation to a new data set using end= data set option.

• Variables/Columns in position order.
• Rows ordered as they appear in data set.

If you don’t want to process certain variables and you do not want them to appear in the new data set, then specify drop = data set option in the set statement.

Whereas If want to process certain variables and do not want them to appear in the new data set, then specify drop = data set option in the data statement.

Use DESCENDING keyword in PROC SORT code.

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

The end of the macro is defined by %Mend Statement

The purpose of using such type of detail is for analysis the elementary at numeric level. It will help you examine how well is the data actually distributed

The DIVIDE function is used to return the division result.

Missover -When the MISSOVER option is used on the INFILE statement, the INPUT statement does not jump to the next line when reading a short line. Instead, MISSOVER sets variables to missing. Truncover - It assigns the raw data value to the variable even if the value is shorter than the length that is expected by the INPUT statement.

Input function – Character to numeric conversion- Input(source,informat).

put function – Numeric to character conversion- put(source,format).

There are basically two functions which are used for Character handling functions namely UPCASE and LOWCASE.

It has only 2 values, 1 for error and 0 for no error.

n-count, mean, standard deviation, minimum, and maximum

The DATA _NULL_ is mainly used to create macro variables. It can also be used to write output without creating a dataset.The idea of "null" here is that we have a data step that actually doesn't create a data set.

It is a bitwise logical operation and is used for returning bitwise logical OR between two statements.

It is used for compressing the data into new output.

It is used for submitting the step of a PROC which is used more specifically in RUN statement. It ends without any kind of process.

Input delimiters are DLM and DSD.

PROC PRINTTO command is used to save logs in the external file.

By using MAXDEC= option

Using the ‘group’ definition isn’t the only way to define the variables. There are quite a few definitions that you can use (i.e. analysis).

• Business Solutions: SAS provides business analysis that can be used as business products for various companies to use.
• Analytics: SAS is the market leader in the analytics of various business products and services.
• Data Access & Management: SAS can also be use as a DBMS software.
• Reporting & Graphics: Hello SAS helps to visualize the analysis in the form of summary, lists and graphic reports.
• Visualization: We can visualize the reports in the form of graphs ranging from simple scatter plots and bar charts to complex multi-page classification panels.

It focuses on Character String Matching to allocate the free memory.

Adding the CROSSLIST option to TABLES statement displays crosstabulation tables in ODS column format.

SET concatenates the data sets where as MERGE matches the observations of the data sets.

No, Proc Means requires at least one numeric variable.

The NODUPKEY option removes duplicate observations where value of a variable listed in BY statement is repeated while NODUP option removes duplicate observations where values in all the variables are repeated (identical observations).

• If the variable is used as group variable, rows that have the same values are collapsed.
• Group variables produce list report whereas order variable produces summary report.

• Using SAS Macros.
• Using a %include statement

32 characters long.

DATA, INPUT, RUN, CARDS ,INFILE,WHERE,LABEL,SELECT,INFORMAT,FORMAT

The main difference is that while reading an existing data set with the SET statement, SAS retains the values of the variables from one observation to the next. Whereas when reading the data from an external file, only the observations are read. The variables will have to re-declared if they need to be used.

The VFORMATX function is used to return the format that is assigned with the value of a given statement.

• SAS is a software suite for advanced analytics, multivariate analyses, business intelligence, data management and predictive analytics
• It is developed by SAS Institute.
• SAS provides a graphical point-and-click user interface for non-technical users and more advanced options through the SAS language.

A RETAIN statement tells SAS not to set variables to missing when going from the current iteration of the DATA step to the next. Instead, SAS retains the values.

PROC MEANS produce the “default” statistics of N, MIN, MAX, MEAN and STD DEV.

CATX syntax inserts delimiters, removes trailing and leading blanks, and returns a concatenated character string.

The scan function searches for a particular string and puts the value in the target variable, the target variable length using the scan function is 200 chars.

There are some system options that can be used to debug SAS Macros: MPRINT, MLOGIC, SYMBOLGEN.

The focus of such function is to search the character string and return it soon after it is found.

Stop statement causes SAS to stop processing the current data step immediately and resume processing statement after the end of current data step.

SUM function returns the sum of non-missing arguments whereas “+” operator returns a missing value if any of the arguments are missing.

It is used for sorting the SAS data for which variable are set. This way, it becomes possible to set a new data for further usage.

To generate list output for crosstabulations, add a slash (/) and the LIST option to the TABLES statement in your PROC FREQ step.

TABLES variable-1*variable-2 <* … variable-n> / LIST;

Debugging is a technique for testing the program logic, and this can be done with the help of Debugger.

You can use the OUTPUT statement to save summary statistics in a SAS data set. This information can then be used to create customized reports or to save historical information about a process.

You can use options in the OUTPUT statement to

• Specify the statistics to save in the output data set,
• Specify the name of the output data set, and
• Compute and save percentiles not automatically computed by the CAPABILITY procedure.

We will use PROC MEANS for numeric variables whereas we use PROC FREQ for categorical variables.

Under this function there are few characters which are specified in a string. They are then replaced with the other characters which are usually specified.

ODS Trace is used to find the names of the particular output objects when several of them are created by some procedure. ODS TRACE ON; ODS TRACE Off;

SCAN extracts words within a value that is marked by delimiters. SUBSTR extracts a portion of the value by stating the specific location. It is best used when we know the exact position of the sub string to extract from a character value.

200

Interleaving combines individual, sorted SAS data sets into one sorted SAS data set.

The CEIL function, when issued, retrieves the smallest integer, while FLOOR does the opposite and retrieves the biggest one.

INFILE, INPUT, Output, Call routines

drop, keep, rename, label, format, informat, attrib, where, by, retain, length, array.

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

1. _NUMERIC_ specifies all numeric variables that are already defined in the current DATA step.
2. _CHARACTER_ specifies all character variables that are currently defined in the current DATA step.

This type of process is more basically used for analysis the data and ensure that whatever is received is accurate and comes without any kind of single error.

Functions expect argument values to be supplied across an observation in a SAS data set whereas a procedure expects one variable value per observation.