WRITE A FUNCTION TO ADD TWO NUMBERS:

CREATE or REPLACE function FUN
(a in number,
 b in number)
Return number
is
c number;
BEGIN
c:=a+b;
Return c;
END;

EXECUTION PROCESS IN SQL:
SQL>var x number; (press enter)
SQL>exec :x:=fun(10,20); (press enter)
then it appear PL/SQL PROCEDURE SUCCESSFULLY COMPLETED
SQL>print x (press enter) THEN IT APPEAR AS BELOW OUTPUT
       X
----------------
           30