20 SAS Macro Interview Questions and Answers

SAS Macro is a powerful programming language that allows developers to automate SAS processes. If you’re applying for a position that involves SAS Macro programming, it’s important to be prepared for questions about your experience and skills. In this article, we’ll review some common SAS Macro interview questions and provide tips on how to answer them.

SAS Macro Interview Questions and Answers

Here are 20 commonly asked SAS Macro interview questions and answers to prepare you for your interview:

1. What is a SAS macro?

A SAS macro is a piece of code that can be reused over and over again. Macros can be used to automate repetitive tasks, or to create new SAS functions that can be used in SAS programs.

2. How do you define or create a macro in SAS?

There are a few different ways to create a macro in SAS. The most common way is to use the %macro statement, which will start the macro definition. You will then use the %mend statement to end the definition. Another way to create a macro is to use the %include statement to include a file that contains the macro definition.

3. Can you explain the difference between macros and functions in SAS?

Macros are written in SAS macro language and are compiled at run time. Functions are written in SAS programming language and are compiled when the program is compiled. Functions can be called from within macros, but macros cannot be called from within functions.

4. What are the basic components of a macro definition in SAS?

The basic components of a macro definition in SAS are the macro name, the macro parameters, and the macro body. The macro name is what you will use to call the macro, and the parameters are the variables that will be passed into the macro. The macro body is the code that will be executed when the macro is called.

5. Can you give me an example of how to use the %macro statement in SAS?

The %macro statement is used to define a macro. A macro is a series of SAS statements that are stored together and can be executed as a single step. The %macro statement is followed by the name of the macro and a list of parameters. The macro definition is ended with a %mend statement.

Here is an example of how to use the %macro statement:

%macro mymacro(param1,param2);
SAS statements;
%mend;

To execute the macro, you would use the %macro statement followed by the name of the macro and the values for the parameters. For example:

%mymacro(value1,value2);

6. How can you include comments in a macro definition?

There are two ways to include comments in a macro definition. The first is to use the %* comment statement, which will comment out everything from the %* to the next semicolon ;. The second way is to use the %nrstr function, which will comment out everything from the %nrstr( to the next %nrstr) .

7. How do you call a macro from another macro in SAS?

There are two ways to call a macro from another macro in SAS. The first is to use the %INCLUDE statement, which will insert the code from the called macro into the current macro. The second is to use the %MACRO statement, which will execute the called macro without inserting its code into the current macro.

8. Can you show me some examples of simple parameterized macros in SAS?

A parameterized macro is a macro that contains at least one macro parameter. A macro parameter is a placeholder for a value that is supplied when the macro is invoked. The macro parameter is replaced with the actual value when the macro is executed.

Here is a simple example of a parameterized macro:

%macro mymacro(param1,param2);
%put param1=¶m1;
%put param2=¶m2;
%mend;

In this example, the macro has two parameters, param1 and param2. When the macro is invoked, the values for these parameters are supplied. For example:

%mymacro(value1,value2);

This would cause the following to be displayed:

param1=value1
param2=value2

9. How can you pass parameters to a macro?

There are a few ways to pass parameters to a macro. The most common way is to use the %macro statement, which will define the macro and the parameters that it will take. You can also use the %mend statement to end the macro definition. Another way to pass parameters to a macro is to use the %let statement, which will assign values to macro variables.

10. Do all arguments to a macro get resolved before execution begins? If not, then which ones don’t, and why?

No, not all arguments to a macro are resolved before execution begins. The ones that don’t get resolved are called “macro variables”, and they are resolved during execution. This is because macro variables can contain expressions that need to be evaluated at runtime in order to produce a value.

11. In what situations would you want to delay the resolution of arguments?

There are a few reasons why you might want to delay the resolution of arguments. One reason is if you want to create a macro that can take a variable number of arguments. Another reason is if you want to be able to pass in macro variables as arguments and have them resolved at runtime. Finally, if you want to be able to pass in SAS functions as arguments and have them resolved at runtime, then you will need to delay the resolution of arguments.

12. Can you explain how data sets are used to store named lists of macro variables?

Data sets can be used to store named lists of macro variables in a couple of different ways. The first way is to use a data set to store the values of macro variables that you want to be able to use across different SAS programs. The second way is to use a data set to store the values of macro variables that you want to be able to use within a single SAS program.

13. Why should one avoid using global macro variables in SAS?

Global macro variables are variables that are available to all SAS sessions. This can lead to issues if multiple users are accessing the same SAS file, as the value of the global macro variable can be changed by one user and affect the code for another user. It is generally best to avoid using global macro variables whenever possible.

14. How do you display messages within a macro when it’s being executed?

You can use the %put statement to display messages within a macro when it’s being executed. The %put statement can be used to display text or the value of a SAS variable.

15. Can you explain what the SYMPUTX routine does in SAS?

SYMPUTX is a routine that can be used to store the value of a SAS variable in a macro variable. This is useful when you want to use the value of a SAS variable in a macro program.

16. Is it possible to write recursive macros in SAS? If yes, then how?

Yes, it is possible to write recursive macros in SAS. This can be done by using the %macro statement within the macro definition itself.

17. When is it preferable to use PROMPT instead of CALL SYMPUTX?

CALL SYMPUTX is generally used when you want to store a value in a macro variable and then use that variable later in your SAS code. PROMPT, on the other hand, is used when you want to display a value on the screen for the user to see.

18. What are the differences between local and global symbols in SAS?

Local symbols are only available within the current SAS session or within the current macro. Global symbols are available to all SAS sessions and can be used by any macro.

19. How is it possible to list all the currently defined symbols in SAS?

The SYMGET function can be used to list all the currently defined symbols in SAS.

20. How do you capture the value returned by a macro?

The %put statement can be used to display the value of a macro variable.