PLS-00103 stuck with this error in pl/sql

Question

I have been trying to display only the odd numbers between two user entered numbers by checking if both the numbers are positive. Here's my pl/sql block :

declare 
    num1 number(3);
    num2 number(3);
begin
    num1 := &num1;
    num2 := &num2;
    
    if (num1 > 0 and num2 > 0) then
        dbms_output.put_line('Both entered numbers are positive');
        dbms_output.put_line('The odd numbers between the two entered positive numbers are : ');
        for i in num1..num2 loop
            if mod(i,2)=0 then
            dbms_output.put_line();
            elsif
            dbms_output.put_line(i);
            end if;
        i := i+1;
        end loop;
    elsif 
        dbms_output.put_line('Both entered numbers are not positive');
    end if;

end;
/
        

But i keep getting error : PLS-00103: Encountered the symbol ";" when expecting one of the following: at line 15; even though after multiple checks I cannot find where the problem is. Any help will be great.

Answer 1

Several errors.

• there should've been ELSE instead of ELSIF
• you can't / shouldn't increase the FOR loop counter manually; Oracle does it automatically

Mistakes have been commented (see code below).

SQL> set serveroutput on
SQL> declare
  2      num1 number(3);
  3      num2 number(3);
  4  begin
  5      num1 := &num1;
  6      num2 := &num2;
  7
  8      if (num1 > 0 and num2 > 0) then
  9          dbms_output.put_line('Both entered numbers are positive');
 10          dbms_output.put_line('The odd numbers between the two entered positive numbers are : ');
 11          for i in num1..num2 loop
 12              if mod(i,2)=0 then
 13              dbms_output.put_line(null);
 14              else --elsif
 15              dbms_output.put_line(i);
 16              end if;
 17          --i := i+1;
 18          end loop;
 19      else --elsif
 20          dbms_output.put_line('Both entered numbers are not positive');
 21      end if;
 22
 23  end;
 24  /
Enter value for num1: 5
Enter value for num2: 10
Both entered numbers are positive
The odd numbers between the two entered positive numbers are :
5
7
9

PL/SQL procedure successfully completed.

SQL>