Macro programs

Question 1

Define a macro program with positional parameters.

Define a macro program with keyword parameters.

When mixing positional and keyword parameters, which one goes first?

Answer 1

Mix: positional parameters go before keyword parameters

%macro macro-name(parameter1, parameter2);

stuff

%mend (macro-name);

%macro macro-name(parameter1=value1, parameter2=value2);

stuff

%mend (macro-name);

Question 2

Which option can you use to create a note in the SAS log when a macro has completed compilation?

Answer 2

OPTIONS MCOMPILENOTE = options;

options:

NONE: default. no message

NOAUTOCALL: note is made except for autocall macros

ALL: note is made for all completed macro compilations

Question 3

How do you call a macro?

Where can you make a macro call within the program?

Does it require a semicolon?

Answer 3

%macroname

Can call a macro anywhere in a program except in DATALINES

Does NOT require a semicolon because it is not a SAS statement.

Question 4

A macro call is processed by the macro processor before any ___ _____ ______ such as DATA steps are compiled or executed

Answer 4

A macro call is processed by the macro processor before any SAS language statements such as DATA steps are compiled or executed

Question 5

When you call a macro, SAS language statements within the macro that are sent to the compiler do not appear in the SAS log. Which option can you use to see this text?

Answer 5

OPTIONS MPRINT;

Default is NOMPRINT

It writes to the SAS log each SAS statement generated by a macro.

Question 6

How do you use MLOGIC? What does it do (5 things)?

Answer 6

OPTIONS MLOGIC;

Default is NOMLOGIC

It traces the flow of execution of your macro, including

• the beginning of macro execution
• the values of macro parameters at invocation
• the execution of each maccro program statement
• whether each %IF condition is true or false
• the end of macro execution

Question 7

How can you place comments inside a macro definition?

Answer 7

Use macro comment statement:

%*comment;

or the good ol’

/*comment*/

Question 8

How do you call a macro with keyword parameters?

Answer 8

%macroname(parameter1=value1, parameter2=value2)

Question 9

How do you use the PARMBUFF option and what does it do?

Answer 9

%macro macroname/parmbuff;

text

%mend;

It allows you to create a macro that can accept a varying number of parameters. The list of parameters, including the parentheses, are stored in automatic macro variable syspbuff, so the text has to have a reference to it (%syspbuff).

Question 10

How do you use the %GLOBAL statement and what does it do?

Answer 10

It can be used inside or outside macro definition.

It creates one or more macro variables in the global symbol table and assigns null values to them

e.g.

%global dsn vars;

Question 11

How do you delete a macro variable from the global symbol table?

Answer 11

%SYMDEL macroname;

Question 12

How can you create a global macro variable (4 ways)?

Answer 12

1. %LET
2. DATA step with SYMPUT
3. SELECT statement with INTO clause in PROC SQL
4. %GLOBAL

Question 13

How do you create local macro variables (5 ways)

What special about the SYMPUT routine?

Answer 13

The SYMPUT routine can only create a local macro variable if a local symbol table already exists. If local symbol table doesn’t exist, SYMPUT creates a global macro variable

1. parameters in a macro definiton
2. %LET within a macro definition
3. DATA step with SYMPUT within a macro definition
4. SELECT statement with INTO clause in PROC SQL within a macro definition
5. %LOCAL

Question 14

%LOCAL

Where can you use it?

What does it do?

Answer 14

You can use it only inside a macro definition.

It creates one or more macro variables in the local symbol table and assigns null values to them

Question 15

What steps does the macro processor go through when you use a %let statement within a macro program (eg. %let macvar=value)?

What if you use the %let statement in open code?

Answer 15

Note: same steps apply when you call a macro, e.g. &macvar

1. The macro processor checks to see if macvar already exists in the local symbol table. If so, it updates macvar in the local symbol table with the value “value.” If macvar doesn’t exist in the local table, it goes on to step 2.
2. The macro processor checks to see if macvar already exists in the global symbol table. If so, it updates macvar in the global symbol table with the value “value.” If macvar doesn’t exist in the global table, it goes to step 3.
3. The macro processor creates a macro variable named macvar in the local symbol table and assigns a value of “value” to it.

If use %let in open code, the macro processor only checks the global symbol table.

Question 16

What is the value of variX and variY in the global and/or local symbol tables?

%macro outer;

%local variX;

%let variX=one;

%inner

%mend outer;

%macro inner;

%local variY;

%let variY = &variX;

%mend inner;

%let variX=zero;

%outer

Answer 16

Note: macro processor checks for macro variables in the most recently created local symbol table first when there are multiple local symbol tables.

In the global symbol table, variX = zero.

In the outer local symbol table, variX = one.

In the inner local symbol table, variY = one.

Question 17

What option allows you to see the macro nesting information in the SAS log as part of the MPRINT output?

Answer 17

Note: MPRINT has to be on as well

MPRINTNEST option

options mprint mprintnest;

Question 18

What option allows you to see macro nesting information in the SAS log as part of the MLOGIC output?

Answer 18

Note: MLOGIC has be on

MLOGICNEST option

options mlogic mlogicnest;

Question 19

Syntax for %IF %THEN %ELSE statements

Answer 19

expression = any valid macro expression that resolves to an integer. If expresssion resolves to zero, then it is false.

%IF expression %THEN text;

(%ELSE text;)

Question 20

Syntax for %DO-%END statements within %IF%THEN%ELSE statement

Answer 20

Note: all these statements can only be used within a macro program

%IF expression %THEN %DO;

text and/or macro language statements

%END;

%ELSE %DO;

text and/or macro language statements

%END;

Question 21

Syntax for iterative %DO statements

Answer 21

index-variable = macro variable name or text expression that generates a macro variable name

%DO index-variable=start %TO stop (%BY increment);

text

%END;

Question 22

How to do calculations within a macro?

Answer 22

Use %EVAL, e.g. %let a=%eval(2+1);

Note: only gives you integers as answers

Use %SYSEVALF to get floats as answers

Question 23

%EVAL does NOT convert the following to numeric values (2)

Answer 23

Numeric strings that contain a period or E notation

SAS date and time constants

Question 24

Syntax to use %SYSEVALF to conver values. What are the conversion types (4)?

Answer 24

%SYSEVALF(expression, conversion-type)

Coversion types: BOOLEAN, CEIL, FLOOR, or INTEGER

CEIL rounds up, FLOOR rounds down

Question 25

If you save your macro program to an external file, how do you call it?

Answer 25

The macro is compiled when the %INCLUDE statement is submitted

First use %INCLUDE statement, then call the macro.

%INCLUDE file-specification (/SOURCE2);

%macroname

Question 26

How do you save a macro program in a SOURCE entry in a SAS catalog?

Answer 26

1. File -> Save As Object. Select desired library
2. If library.Mymacs catalog does not already exist, create it.
3. Enter macroname in the Entry Name field. Make sure entry type is set to SOURCE entry (SOURCE), and click Save.

Question 27

How do you see the macros that you’ve stored in a SAS catalog?

Answer 27

Note cat= is short for catalog=

PROC CATALOG CATALOG = libref.catalog;

CONTENTS;

QUIT;

Question 28

How do you compile and call a macro stored in a SOURCE entry of a SAS catalog?

Answer 28

entry-type is source

FILENAME macroname

CATALOG‘libref.catalog.macroname.entry-type’;

%INCLUDE macroname;

%macroname

Question 29

How do you compile and call two macros stored in a SOURCE entry of the same SAS catalog?

Answer 29

FILENAME fileref CATALOG‘libref.catalog.’;

%INCLUDE fileref(macroname1);

%INCLUDE fileref(macroname2);

%macroname1

%macroname2

Question 30

How do you save a macro to an autocall library?

Answer 30

1. Make a folder that will hold the macro
2. Save macro as macroname and file type .sas

Question 31

True or False: If a macro is stored in an autocall library, you do not need to submit or include the macro definition before you submit a call to the macro

Answer 31

True

Question 32

How do you call a macro in an autocall library?

Answer 32

filepath points to the folder that contains your macro

options mautosource sasautos = (‘filepath’, sasautos);

%macroname

Question 33

How do you create a permanently stored compiled macro?

Answer 33

1. Assign a libref to the SAS library in which the compiled macro is stored
2. set the system options MSTORED and SASMSTORE=libref
3. use the STORE option in the %MACRO statement when you submit the macro definition:

%macro macro-name /STORE;

text

%mend;

Question 34

How do you store the source code of the compiled macro with the compiled macro code?

Answer 34

SOURCE option

libname macrolib ‘file-path’;

options mstored samstore=macrolib;

%macro macro-name /store source;

…

Question 35

How do you call a stored compiled macro?

Answer 35

1. Assign a libref to the SAS library that contains a Sasmacr catalog in which teh macro was stored
2. set the system options MSTORED and SASMSTORE=libref
3. call the macro

Question 36

Which is the only catalog in which compiled macros can be stored?

Answer 36

You can create a Sasmcr catalog in any SAS library

Sasmcr

Question 37

How can you write the source code of a compiled macro to the SAS log (assume you used SOURCE option when storing macro definition)?

Answer 37

%copy macro-name/source;