SAS: Hash table lookup

SAS hash table lookup example taken from http://support.sas.com/documentation/cdl/en/lrcon/65287/HTML/default/viewer.htm#n1b4cbtmb049xtn1vh9x4waiioz4.htm and included in this bog so I can find it easily.


data match;
   length k 8;
   length s 8;
   if _N_ = 1 then do;
      /* load SMALL data set into the hash object */
     declare hash h(dataset: "work.small");
      /* define SMALL data set variable K as key and S as value */
      h.defineKey('k');
      h.defineData('s');
      h.defineDone();
      /* avoid uninitialized variable notes */
      call missing(k, s);
   end;

/* use the SET statement to iterate over the LARGE data set using */
/* keys in the LARGE data set to match keys in the hash object */
set large;
rc = h.find();
if (rc = 0) then output;
run;