OPTIONS LINESIZE=88 PAGESIZE=53 NOCENTER NODATE NONUMBER NOFMTERR;
*******************************************************************;
* PROJECT NAME: Learning to Use SAS                                ;
*             PROGRAM NAME     LOCATION     DATE     PROGRAMMER    ;
TITLE1 "Source:LEC19P5.SAS    Disk 1998#1 11/4/98       EJS "      ;
* Description: Converting character variables to numeric           ;
*******************************************************************;

PROC FORMAT;
  VALUE instudyf 0="No"
                 1="Yes";

DATA d1 ;
  INPUT @1 id          2.
           age        $5.
        @9 bdate MMDDYY8.;
  cdate=MDY(11,1,95);
  agen=INT((cdate-bdate)/365.25);

  *********************************************;
  *** Set age equal to birthdate age if present;
  *** Otherwise, use the self reported age ;
  *********************************************;
  IF bdate NE . THEN agef=agen;
    ELSE IF age NE . THEN agef=age;

  *********************************************;
  *** Create a variable that indicates if the ;
  *** recoded age is within the 18-24 range ;
  *********************************************;
  IF 18 LE agef LE 24 THEN instudy=1;
    ELSE instudy=0;
  LABEL  age="Char/Age:/AGE"
       bdate="Birth/Date:/BDATE"
       cdate="Study/Date:/CDATE"
        agen="Num/Age/From/BDATE/At/Study/Start:/AGEN"
        agef="Best/Age:/AGEF"
     instudy="Subject/In the/Study?:/INSTUDY";

  FORMAT instudy instudyf.;

CARDS;
01 22   12/16/72
02 >18   .
03 21   4/10/75
04 unkn  .
05 24    .
06 25   10/9/70
;


PROC PRINT DATA=d1 SPLIT="/";
  ID id;
  VAR  age agen agef instudy;
  TITLE2 "Table 1.  List of Character Age (age) and Numeric Age (agen)";

RUN;