SQL> ED
Wrote file afiedt.buf

  1  create or replace procedure
  2  test
  3  (C in NUMBER default null)
  4  is
  5  cursor c1 is select * from emp where COMM=C;
  6  begin
  7  for mag in c1 loop
  8  exit when c1%notfound;
  9  dbms_output.put_line(mag.sal);
 10  end loop;
 11* end;
SQL> /

Procedure created.

SQL> EXEC TEST(500);
1250

PL/SQL procedure successfully completed.

SQL> EXEC TEST

PL/SQL procedure successfully completed.

SQL>