The SAS TM SUBSTR Function A Beginner’s Tutorial

The SUBSTR Function focuses on a portion of a string can go on either side of the “=” sign! SYNTAX: SUBSTR(ARGUMENT, POSITION, N) returns N characters, beginning at character number POSITION from the string ARGUMENT .

focuses on a portion of a string

can go on either side of the “=” sign!

SYNTAX: SUBSTR(ARGUMENT, POSITION, N) returns N characters, beginning at character number POSITION from the string ARGUMENT .

First use pulls from the variable PHONE Second pulls from hard-coded string Third pulls from a macro variable The result: ‘312’ assigned to the variable AREA_CD each time Common SUBSTR Function Applications %let phone = (312) 555-1212 ; data _null_ ; phone = ‘(312) 555-1212’ ; area_cd = substr(phone, 2, 3) ; area_cd = substr(‘(312) 555-1212’, 2, 3) ; area_cd = substr(“&phone”, 2, 3) ; run ; SAMPLE CODE

First use pulls from the variable PHONE

Second pulls from hard-coded string

Third pulls from a macro variable

The result: ‘312’ assigned to the variable AREA_CD each time

Also Works On the “Left-Hand” Side of the “=” Sign. VAR1 changes from ‘12345’ to ’17845’ Can “put into” a variable just as easily as it can “extract out of” a variable 1 data _null_ ; 2 var1 = '12345' ; 3 var2 = '67890' ; 4 substr(var1, 2, 2) = substr(var2, 2, 2) ; 5 put var1 = var2 = ; 6 run ; VAR1=17845 VAR2=67890 NOTE: DATA statement used: real time 0.13 seconds cpu time 0.05 seconds

VAR1 changes from ‘12345’ to ’17845’

Can “put into” a variable just as easily as it can “extract out of” a variable

Common Mistakes: Value Too Large for N N (7) > length VAR1 ( $5) “ Invalid third argument ... ” Note Length of VAR1 passed to the length of VAR2 SUBSTR function pulls as much as possible from the starting POSITION parameter 1 data _null_ ; 2 var1 = '12345' ; 3 var2 = substr(var1, 2, 7) ; 4 run ; NOTE: Invalid third argument to function SUBSTR at line 3 column 11. VAR1=12345 VAR2=2345 _ERROR_=1 _N_=1

N (7) > length VAR1 ( $5)

“ Invalid third argument ... ” Note

Length of VAR1 passed to the length of VAR2

SUBSTR function pulls as much as possible from the starting POSITION parameter

Common Mistakes: Value Too Large for POSITION POSITION (7) > length VAR1 ( $5) “ Invalid second argument ... ” Note Length of VAR1 passed to the length of VAR2 SUBSTR function pulls as much as called (in this case 2) from the starting POSITION of 1 1 data _null_ ; 2 var1 = '12345' ; 3 var2 = substr(var1, 7, 2) ; 4 run ; NOTE: Invalid second argument to function SUBSTR at line 3 column 12. VAR1=12345 VAR2=12 _ERROR_=1 _N_=1

POSITION (7) > length VAR1 ( $5)

“ Invalid second argument ... ” Note

Length of VAR1 passed to the length of VAR2

SUBSTR function pulls as much as called (in this case 2) from the starting POSITION of 1

Common Mistakes: Value not Positive Integer POSITION (-2) is not a Positive Integer “ Invalid second argument ... ” Note Length of VAR1 passed to the length of VAR2 SUBSTR function pulls as much as called (in this case 1) from the starting POSITION of 1 1 data _null_ ; 2 var1 = '12345' ; 3 var2 = substr(var1, -2, 1) ; 4 run ; NOTE: Invalid second argument to function SUBSTR at line 3 column 12. VAR1=12345 VAR2=1 _ERROR_=1 _N_=1

POSITION (-2) is not a Positive Integer

“ Invalid second argument ... ” Note

Length of VAR1 passed to the length of VAR2

SUBSTR function pulls as much as called (in this case 1) from the starting POSITION of 1

Troubleshooting Summary Any deviation from valid arguments results in a NOTE and not a WARNING or ERROR message in the SAS Log Any occurrence of an invalid argument results in all variables from that observation being written to the log Be sure to check your log each time you use the SUBSTR function

Any deviation from valid arguments results in a NOTE and not a WARNING or ERROR message in the SAS Log

Any occurrence of an invalid argument results in all variables from that observation being written to the log

Be sure to check your log each time you use the SUBSTR function

About the Author SPIKEware, Inc. 115 ½ West Main Street West Dundee, IL 60118 Phone (847) 428-6250 Fax (847) 428-6270 SPIKEware, Inc. is a consulting firm dedicated to helping other people solve their problems through technology. We specialize in providing solutions for our customers through the SAS Software System. http://www. SPIKEware .com/ Paul D. McDonald is the CEO of SPIKEware, Inc. and has been a SAS programmer since 1993. Paul has an A.A. in Electrical Engineering from Cloud County Community College, a B.A. in Physics from Southwestern College, and an M.B.A. in Finance from Keller Graduate School of Management. Paul can be reached by e-mail at PDM@SPIKEware.com

SPIKEware, Inc.

115 ½ West Main Street

West Dundee, IL 60118

Phone (847) 428-6250

Fax (847) 428-6270

SPIKEware, Inc. is a consulting firm dedicated to helping other people solve their problems through technology. We specialize in providing solutions for our customers through the SAS Software System.

http://www. SPIKEware .com/