G-4370: Avoid using EXIT to stop loop processing unless you are in a basic loop.

Major

Maintainability

Reason

A numeric for loop as well as a while loop and a cursor for loop have defined loop boundaries. If you are not able to exit your loop using those loop boundaries, then a basic loop is the right loop to choose.

Example (bad)

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declare
   i integer;
   k_min_value constant simple_integer := 1;
   k_max_value constant simple_integer := 10;
   k_increment constant simple_integer := 1;
begin
   i := k_min_value;
   <<while_loop>>
   while (i <= k_max_value) 
   loop 
      i := i + k_increment; 
      exit while_loop when i > k_max_value;
   end loop while_loop;

   <<basic_loop>>
   loop 
      exit basic_loop;
   end loop basic_loop;

   <<for_loop>>
   for i in k_min_value..k_max_value
   loop 
      null;
      exit for_loop when i = k_max_value;
   end loop for_loop;

   <<process_employees>>
   for r_employee in (select last_name
                        from employee)
   loop
      sys.dbms_output.put_line(r_employee.last_name);
      null; -- some processing
      exit process_employees;
   end loop process_employees;
end;
/

Example (good)

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declare
   i integer;
   k_min_value constant simple_integer := 1;
   k_max_value constant simple_integer := 10;
   k_increment constant simple_integer := 1;
begin
   i := k_min_value;
   <<while_loop>>
   while (i <= k_max_value) 
   loop 
      i := i + k_increment; 
   end loop while_loop;

   <<basic_loop>>
   loop 
      exit basic_loop;
   end loop basic_loop;

   <<for_loop>>
   for i in k_min_value..k_max_value
   loop 
      sys.dbms_output.put_line(i);
   end loop for_loop;

   <<process_employees>>
   for r_employee in (select last_name
                        from employee)
   loop
      sys.dbms_output.put_line(r_employee.last_name); -- some processing
   end loop process_employees;
end;
/