No. of vowels and consonants in a given string in PL/SQL

I have done this question by two methods

• By using loops

declare
counts number :=0;
counts1 number :=0;
str1 varchar2(500) :=LOWER('This is the string');
begin
  for i in 1..length(str1)
    loop
     if(substr(str1,i,1) in ('a','e','i','o','u'))
      then
        counts := counts + 1;
          else
         counts1 := counts1 + 1;
      end if;   
    end loop;
    dbms_output.put_line('Input : '||str1);
    dbms_output.put_line('Total vovels :' ||counts);
    dbms_output.put_line('Total consonants :' ||counts1);

end;     

• By using regular expressions

declare
counts number := 0;
counts1 number := 0;
str1 varchar2(500) := lower('This is the string');
begin
select length(regexp_replace(str1,'[^aeiou]')) as total_vovels into counts from dual;
select length(regexp_replace(str1,'[aeiou]'))  as total_consonants into counts1 from dual;
dbms_output.put_line('Total vovels :'||counts);
dbms_output.put_line('Total consonants :'||counts1);
end;