The ELSE clause can be replaced by an EXCEPTION part.
SQL> SQL> DECLARE-- w ww . j ava2 s . c o m 2 final_mark CHAR(1); 3 BEGIN 4 final_mark := 'B'; 5 6 CASE 7 WHEN final_mark = 'A' THEN DBMS_OUTPUT.PUT_LINE('Excellent'); 8 WHEN final_mark = 'B' THEN DBMS_OUTPUT.PUT_LINE('Very Good'); 9 WHEN final_mark = 'C' THEN DBMS_OUTPUT.PUT_LINE('Good'); 10 WHEN final_mark = 'D' THEN DBMS_OUTPUT.PUT_LINE('Fair'); 11 WHEN final_mark = 'F' THEN DBMS_OUTPUT.PUT_LINE('Poor'); 12 END CASE; 13 EXCEPTION 14 WHEN CASE_NOT_FOUND THEN 15 DBMS_OUTPUT.PUT_LINE('No such final_mark'); 16 END; 17 / Very Good PL/SQL procedure successfully completed. SQL> SQL>