FUNCTION OVERLOADING

Function Overloading in Polymorphism:
A Package containing many functions with same function name and having different types of parameters or different no of same type of parameters is called Function Overloading.

Example:

Create or replace Package mypack
IS
Function fun(a in number,b in number)
Return Number;
Function(a in nember,b in number,c in number)
Return Number;
Function fun(a in number, b in number, c in number, d in number)
Return Number;
End;

Create or Replace Package Body mypack
IS
Function fun(a in number,b in number)
Return number
IS
C number;
Begin
C:=a+b;
End fun;
Function fun(a in number, b in number, c in number)
Return number
IS
D number;
Begin
D:=a+b+c;
End fun;
Function fun(a in number, b in number, c in number, d in number)
Return number
IS
E number;
Begin
E:=a+b+c+d;
End fun;
End;

EXECUTION:
SQL>  var  x  number
SQL>  exec  :x:=mypack.fun(10,20)
PL/SQL Procedure successfully completed
SQL>  Print x
               X
----------------------
                     30
SQL>/
SQL> var  x  number
SQL> exec :x:=mypack.fun(10,20,30)
PL/SQL Procedure successfully completed
SQL> Print  x
                  X
------------------------
                     60