DTUG SAS-Cert-Exam

1-32 characters long, can contain letters in upper or lower can, underscores ( _ ) and numbers

True

a descriptor portion and a data portion

name of the dataset, date and time the dataset was created, number of observations, number of variables

observations (rows), variables (columns), contains missing values (“” or ., for characters and numeric respectively)

name (which follows the same rules as dataset names), type (either character or numeric), length (characters up to 32767 bytes long and numeric are all length 8)

Additionally variables can have a format (which specifies the way the data is written and its width and the number of decimal points if numeric), an informat (which transforms variables written in a specific format to remover characters [$, , ] from numeric variables) and a label (which is descriptive text to describe the variable up to 256 characters)

listing (the traditional output) and HTML

Sashelp, Sasuser, Work

use the libname statement with a name for the library (1-8 characters long and following dataset name rules) and a file location

the Explorer, Log, Output, Results and editing windows (i.e., the Enhanced Editor and Program Editor )

Proc Contents data=filename nods
run;

nods

Proc Datasets can also be used and overlaps in most functionality.
Proc Datasets <options>; Contents <options>;
quit;
It can can only reference the library stipulated in its data=option

VARNUM. For example,
proc contents data=dsname
order=varnum;
run;

Using an Options statement
For example:
options pagesize=60;

line size, page size, display of page numbers, display of date and time
For example:
options pagesize=60 linesize=80 pageno=1 nodate nocenter;

Date/nodate

Number/nonumber

Pageno

Pagesize
For example:
options pagesize=60;

The options statement should NOT appear inside a data step or a proc step
The pagesize option (synonym ps) sets the number of lines per page in the SAS output window

Linesize
The linesize option is used in either the infile statement or in the options statement.
Used in the infile statement, the linesize option sets the length of the line read from a data file. Default is 80
Used in the options statement, the linesize option sets the width of lines written to the output window

Yearcutoff

Firstobs

Obs

Formchar

Formdlim

Label/nolabel

Replace/noreplace

Source/nosource

Yes

#2

#2

ID

True

True

None.

In a where clause, it selects observations that include the specified substring

PROC SORT data= <sas dataset set> out= <new dataset>;
By [descending] VAR(s);
run;

False. You do NOT have to name the VARs in a VAR statement if you specify them in the SUM statement. For Example:
PROC PRINT data= help.snacks;
VAR Price Advertised Holiday Date Product ;
Where QtySOld > 65 and Holiday=1;
SUM QtySold;
run;

True. For example:
PROC PRINT data= snacks;
VAR Price Advertised Holiday Date Product;
SUM QtySold;
by advertised holiday;
run;

Use PAGEBY. For example:
PROC PRINT data= snacks;
VAR Price Advertised Holiday Date Product;
where QtySold > 65;
SUM QtySold;
by advertised holiday;
Id advertised holiday;
PAGEBY advertised ;/* only works with one VAR */
run;

use DOUBLE option. For example:
PROC PRINT data= help.snacks(obs=10) double;
VAR QtySold Price Advertised Holiday Date Product;
run;

FALSE

10

10

True

Use a NULL TITLE or FOOTNOTE. For example:
title1 "David's favorite data set”;
title3 "Cris is writing another check SAS program!";
PROC PRINT data= esdb.herdata (obs=20) ;
VAR COCODE SSCODE Value Year;
run;
title;

Use the LABEL statement.

The LABEL option in PROC PRINT specifies that the labels are displayed. For example:
PROC PRINT data= esdb.dotdata(obs=20)label ;
Label COCODE= ‘ESDB country code’
SSCODE= ‘ESDB series code’;
run;

True

True

False. you MUST add the label option in the PROC PRINT! For example:
PROC PRINT data= inside_dataset label;
run;

Together with a LABEL statement, it tells where the text splits

True. For Example:
PROC format;
value value_fmt
1= 'Free'
2= 'Partly Free'
3= 'Not Free';

COMMAw.d

Example: comma8.2

DOLLARw.d

Example: dollar6.2

MMDDYYw.

Example: MMDDYY10.

w.

Example: 7.

w.d

Example: 8.2

$w.

Example: $12.

DATEw.

Example: date9.

True

Fixed fields - values for each variable are in the same location in all records.
Column input - specifies actual column location for values

input ActLevel $ 9-12 Age 6-7;

1.Operand
2.Operator

1.Highest. negative prefix, exponention
2.Second priority. Multiplication, division
3.Third priority. Addition, substraction

False. Dates are stored as numeric. Without the D, a date would be stored as character, therefore not recognized as a date. e.g., '26oct2010'd

False. INFILE is used for reading external files. DATALINES is used to read instream data

False. Use File and PUT to OUTPUTTING DATA FROM SAS TO EXTERNAL FILES. Use INFILE and INPUT for reading in data

True. e.g.,
LIBNAME dtug_xl 'S:\Esdb_Source\Results.xls';

True. e.g.,
SET dtug_xl.'Ranking_N_10$'n
The N tells SAS it's a name. Hence, this is called a SAS name literal.

To describe the contents of an entire library use the reserved keyword _all_:
PROC CONTENTS DATA=esdb._all_;
RUN;

GETNAMES-determines whether or not to use the first row of data in Excel as column names
SCANTEXT-specifies whether to read the entier data columnand use the length of the longest string found as the SAS column width
MIXED-specifies whether to import data with both character and numeric values and conver everything to character

1)creation of IB,
2)creation of PDV
3)syntax checking

creation of physical SAS dataset (or _NULL_ data set)

1. LIBRARY=libref. Use libref to declare a permanent store. LIBRARY can be abbreviated to LIB
2. FMTLIB. Prints contents of a format catalog

Place a '$' before format-name.

range of numeric values, such as 0-1500

if it's a range of character, then the values must be enclosed in quotes, such as ‘A’-‘M’. If it’s a range of character, the format name must start with a dollar sign ($)

False. You CANNOT be a combination of character and numeric values

None. They are all true

They are all true.

TEMP library

DELETE formats using PROC CATALOG or the SAS Explorer window

A period is required after value_fmt. in order to associate the user-defined format with a variable in a FORMAT statement---i.e.,
Format value value_fmt.;

1. $w.
2. w.d
3. COMMAw.d
4. DOLLARw.d

1.MMDDYY6.
010160

2.DDMMYY8.
31/12/60

3.DATE9.
31DEC1959

4.WEEKDATE.
Friday, January 1, 1960

All of the above are TRUE

Use a WHERE clause.

False. Can use 1 or MORE DEFINE statements in ANY order and you can use options (usage, attributes, etc.) in ANY order within the DEFINE statement

SIngle quotes are required for 'Country/Code'. ’column-heading’ = label for column heading
Specify in quotes. Can use a slash or specify split option to split column headings.

Usage is established in DEFINE statement

True

proc means
proc summary
proc freq

False. Proc means in its most basic form provides an n count, mean, standard deviation, maximum and minimum for all numeric variables, EVEN year if it’s there.

To specify variables in the proc means, you use the var statement:

proc means data=undex mean range std maxdec=3;
var value;
run;

There are two statements that can group descriptive statistics: class and by

proc means data=undex mean range std maxdec=3;
var value;
class year sscode;
run;

The other option is to use by, however, variables must be sorted by the by variable before it is used.

proc means data=undex mean range std maxdec=3;
var value;
by year sscode;
run;

All it requires us to do is add the following line of code:

proc means data=undex maxdec=3;
var value;
by year sscode;
output out=work.undtest
mean=avgval;
run;

Proc summary has all the same functions and options as proc means, it just won’t produce report window output (unless you specific the print option)

Proc freq can produce 1 to n-way tables describing, primarily, the number of observations.

Crosstabulation tables can also be created. The basic form is:

proc freq data=<dataset> <options>;
run;

To specify the variables, we use the tables statement, which is best for categorical variables (i.e. year, sscode).

proc freq data=undex;
tables year cocode sscode;
run;

A two-way table is done as follows:

proc freq data=undex;
tables year*sscode;
run;

ods listing close; (if you don’t want listing output)
ods listing; (to reset ODS to listing default)
ods _all_ close; (Closing Multiple ODS Destinations)

ODS HTML
BODY= file-specification
CONTENTS=contents-file-specification
FRAME=fram-file-specification;
ODS HTML CLOSE;

1)PATH option
2)STYLE option

Variable + Expression. Variable specifies the name of the accumulator variable.

Use the RETAIN statement to initialize variables--i.e.,:

RETAIN variable <initial-value>;

retain cum_total_fa 314911551;

To perform an action conditionally or assign a value conditionally, use an IF-THEN statement

if cocode = '6RWA' then Country = 'Rwanda';

Specify an alternative action using else statement

Use LENGTH to specify a length for a variables:
LENGTH variables(s) <$> length;

Delete unwanted observations using:
IF expression THEN DELETE;

Use the KEEP or DROP statement

data example7 (drop=cocode);
set example6;
run;

Use the LABEL statement

data example8 ;
set example7;
label fa = 'Foreign Assistance';
run;

Use SELECT groups in DATA steps to perform conditional processing

select (Country);
when ('Rwanda') Region='Africa';
otherwise Region='LA';
end;

To execute a group of statements as a unit use DO Groups

do;
amount= 'HIGH FA';
review = 'Y';
end;

1. sort the data
2. FIRST.variable is 1 for the first observation in a BY GROUP, 0 for any other observation
3. LAST.variable is 1 for the last observation in a BY GROUP, 0 for any other observation

To access observations directly, use POINT= with STOP (to avoid continuous looping)
DATA <work.data-set>;
Obsnum= value; (must be before SET statement)
SET <dataset> POINT=obsnum;
STOP; (must use to prevent endless looping)
Run;

Use OUTPUT statement to override default way the DATA step writes observations to output
DATA <work.data-set>;
Obsnum= value; (must be before SET statement)
SET <dataset> POINT=obsnum;
OUTPUT;
STOP; (must use to prevent endless looping)
Run;

If you want to determine when the last observation has been read, use END= option in SET statement
DATA <data-set>;
SET <data-set> end= last;
run;

False. Do not use END= option and the POINT= option together. They are incompatible in the same SET statement.

Compilation:
1.PDV is created including _N_ and _ERROR_
2.scan for syntax errors
3.each variable is added to the PDV
4.compilation ends with end of dataset is reached

Execution:
1.At beginning, _N_ =1, _ERROR_=0, and all variables are assigned missing
2.values are added
3.computed values are added

Use SET or PROC APPEND. PROC APPEND only allows appending two data sets
PROC APPEND BASE=esdb.frhdata DATA=work.update_frhdata FORCE;
RUN;

DATA dtug;
SET esdb.frhdata work.update_frhdata;
RUN;

USE SET OR MERGE for:
1)one-to-one reading
2)interleaving
3)match-merging

DATA dtug;
SET esdb.frhdata;
SET esdb.herdata;
more SET statements as necessary...
RUN;

This is done to put observations next to each other until SAS encounters the end of any of the input data sets

DATA interleaved;
SET frh
her
;
BY COCODE YEAR;
RUN;

Reads ALL input data so that the output data set contains the total number of input observations. Sorting is required.

DATA matchmerge;
MERGE frh
her
;
BY COCODE YEAR;
RUN;

SAS sequentially checks each observation of each data set to see whether the BY values match, then writes the combined observation

Use the IN= variable, which is temporary.
DATA matchmerge;
MERGE frh(in=a) Her(in=b);
BY COCODE YEAR;
IF a and b;
RUN;

All of the above

w.d

BEST12.

Use INPUT (source, informat). source and informat are required

Use PUT (source, format). source and informat are required

# seconds since midnight on Jan 1, 1960

False. The default YEARCUTOFF= is 1920.

Returns the number of time intervals in a given time span
INTCK(‘interval’, from, to)

Applies multiples of a given interval to a date, time or datetime and returns the resulting value
x=intnx(‘interval’, start-from, increment, <’alignment’>);

Returns a specified word from a character value
SCAN(argument, n, <delimiters>)

Extract a portion of a character value OR replace the contents of a character value
SUBSTR(argument, position, <n>)

Trims trailing blanks from character values
TRIM(argument)

Concatenates character strings, removes leading and trailing blanks, and inserts separators
CATX (separator, string-1, <…string-n>)argument)

Searches a character value for a specific string
INDEX (source, excerpt)

Searches for a specific substring of characters within a specified character string
FIND (string, substring, <modifiers>, <startpos>)

Replaces or removes all occurrences of a pattern of characters within a character string
TRANWRD (source, target, replacement)

Returns the integer portion of a numeric value – any decimal portion is discarded
INT(argument)

Rank=int(avrank);
Avrank=3.755
Rank=3

Round to nearest specified unit
ROUND(argument, round-off-unit)

Year = 21

False. Only 20 rows are produced

The two options are the Until Statement and While Statement. The main differences is that the Until statement is evaluated at the end of the loop, meaning the loop will always execute once, and the While statement is evaluated at the beginning, meaning the loop might not be executed.

100 observations

ARRAY array-name{dimension} <elements>;
For example:
array X_Years{4} X_2000 X_2001 X_2002 X_2003;

Use a do loop:
array X_Years{4} X_2000 X_2001 X_2002 X_2003;
do i=1 to 4;
X_Years{i}=0.7734*X_Years{i};
end;

temp and catx

Add a '$'. For example:
array country_name{3} $;

ANS: 2 because only 2 variables are characters

Temporary array elements will NOT create new variables that appear in the resulting data set
For example:
array euro_convert{4} _temporary_ (1.0827 1.1166 1.0575 0.8840);

The default length assigned is 8. Assign your own length by specifying the length after the dollar sign array firstname{5} $ 24;

I_2002

INPUT variable <$> startcol-endcol ;
$ - identifies the type as character if appears

You should use FORMATTED INPUT, which uses column pointer controls to position the input pointer on specified column(s)

It consists of 1) @n is an absolute pointer; 2) +n is a relative pointer

INFORMATS

1) Character value formats - $w.
2) Standard numeric data – w.d
3) Nonstandard numeric -e.g., COMMAw.d

It's used when reading variable-length recods that contain fixed field data. The PAD option pads each record with blanks so that all data lines ahve the same length

1)Fixed fields
2)Free-format

Fixed fields

Free-format data

1)Column
2)Formatted
3)List

INPUT variable1 <$> variable2 <$> … variablen <$>;

None are false. They are all true.

1. DLM= place the delimiter in quote marks
2. MISSOVER missing values at the end of a record
3. DSD Reading missing values in the beginning or middle of a record

Modified list input

Jan. 1, 1960

Respective Date INFORMATS:
DATEw.
MMDDYYw.
DDMMYYw.
YYMMDDw.

#3 is false. SAS DOES NOT adjust for daylight saving time.

INPUT <pointer-control> variable informat.;

TRUE

1920

use the forward slash (/) line pointer control to read the records in a raw data file sequentially

use the pound-n (#n) line pointer control to read the records in a raw data file non-sequentially

a Line Pointer Control

True

1. Repeating blocks
2. one ID field with repeat fields
3. Varying number of repeating fields

Line-Hold Specifiers hold the current record to produce list output (e.g., @ or @@)

True. A double trailing @@ should only be used with list input (and not column input); otherwise, and infinite loop can result. Do not use it with MISSOVER

False. The single trailing @ and the double trailing @ are mutually exclusive. Do not use them together

1) the end of the line or record
2) until it hits an INPUT statement with no line-hold specifiers

1) An INPUT statement with no trailing @
2) The bottom of the Data Step

RETAIN

Trailing @

IF - THEN - ELSE

_N_

OUTPUT

Sum statement

END=

DROP=