SQL> --write a procedure to print the summation of two numbers passed as parameters
SQL> ed
Wrote file afiedt.buf

  1  create or replace procedure proc_sum(p1 number,p2 number)
  2  is
  3  begin
  4    dbms_output.put_line(p1+p2);
  5  exception
  6    when others then
  7      dbms_output.put_line('error');    
  8* end;
SQL> /

Procedure created.

SQL> --run the procedure
SQL> --(in sql*plus)
SQL> execute proc_sum(34,67)
101                                                                             

PL/SQL procedure successfully completed.

SQL> --call the procedure from another pl/sql block
SQL> begin
  2    proc_sum(34,67);
  3  end;
  4  /
101                                                                             

PL/SQL procedure successfully completed.

SQL> ed
Wrote file afiedt.buf

  1  declare
  2   a number := 5;
  3   b number := 7;
  4  begin
  5    proc_sum(a,b);
  6* end;
SQL> /
12                                                                              

PL/SQL procedure successfully completed.

SQL> ed
Wrote file afiedt.buf

  1  declare
  2   a number := 5;
  3   b number := 7;
  4  begin
  5    b:=proc_sum(a,b);
  6* end;
SQL> /
  b:=proc_sum(a,b);
     *
ERROR at line 5:
ORA-06550: line 5, column 6: 
PLS-00222: no function with name 'PROC_SUM' exists in this scope 
ORA-06550: line 5, column 3: 
PL/SQL: Statement ignored 


SQL> ed
Wrote file afiedt.buf

  1  declare
  2   a number := 5;
  3   b number := 7;
  4  begin
  5    dbms_output.put_line( proc_sum(a,b) );
  6* end;
SQL> /
  dbms_output.put_line( proc_sum(a,b) );
                        *
ERROR at line 5:
ORA-06550: line 5, column 25: 
PLS-00222: no function with name 'PROC_SUM' exists in this scope 
ORA-06550: line 5, column 3: 
PL/SQL: Statement ignored 


SQL> --wrıte a procedure that accepts two values as ınput parameters
SQL> --and prınt the hıgher of the two valşues on screen
SQL> ed
Wrote file afiedt.buf

  1  create or replace procedure proc_higher(p1 number,p2 number)
  2  is
  3   v_max number;
  4  begin
  5     if p1<p2 then
  6         v_max := p2;
  7      else
  8          v_max := p1
  9      end if;
 10     dbms_output.put_line(v_max);
 11  exception
 12    when others then
 13      dbms_output.put_line('error');
 14* end;
SQL> /

Warning: Procedure created with compilation errors.

SQL> sho err
Errors for PROCEDURE PROC_HIGHER:

LINE/COL ERROR                                                                  
-------- -----------------------------------------------------------------      
9/5      PLS-00103: Encountered the symbol "END" when expecting one of the      
         following:                                                             
         . ( * @ % & = - + ; < / > at in is mod remainder not rem               
         <an exponent (**)> <> or != or ~= >= <= <> and or like like2           
         like4 likec between || multiset member submultiset                     
         The symbol ";" was substituted for "END" to continue.                  
                                                                                
SQL> ed
Wrote file afiedt.buf

  1  create or replace procedure proc_higher(p1 number,p2 number)
  2  is
  3   v_max number;
  4  begin
  5     if p1<p2 then
  6         v_max := p2;
  7      else
  8          v_max := p1;
  9      end if;
 10     dbms_output.put_line(v_max);
 11  exception
 12    when others then
 13      dbms_output.put_line('error');
 14* end;
SQL> /

Procedure created.

SQL> begin
  2     proc_higher(2,78);
  3  end;
  4  /
78                                                                              

PL/SQL procedure successfully completed.

SQL> ed
Wrote file afiedt.buf

  1  begin
  2     proc_higher(&anumber,&anotherone);
  3* end;
SQL> /
Enter value for anumber: 12
Enter value for anotherone: 89
old   2:    proc_higher(&anumber,&anotherone);
new   2:    proc_higher(12,89);
89                                                                              

PL/SQL procedure successfully completed.

SQL> /
Enter value for anumber: 1
Enter value for anotherone: 1
old   2:    proc_higher(&anumber,&anotherone);
new   2:    proc_higher(1,1);
1                                                                               

PL/SQL procedure successfully completed.

SQL> ed
Wrote file afiedt.buf

  1  begin
  2     proc_higher(&78,&12);
  3* end;
SQL> /
Enter value for 78: 45
Enter value for 12: 96
old   2:    proc_higher(&78,&12);
new   2:    proc_higher(45,96);
96                                                                              

PL/SQL procedure successfully completed.

SQL> spool off