Count odd and even digits in a number in PL/SQL

Prerequisite – PL/SQL introduction
In PL/SQL code groups of commands are arranged within a block. A block group related declarations or statements. In declare part, we declare variables and between begin and end part, we perform the operations.
Given a number and task is to find the number of odd and even digits present in the number. 

Examples:

Input: 123456
Output: Odd digits = 3
        Even digits = 3

Input: 246
Output: Odd digits = 0
        Even digits = 3

Approach is to take a number and one by one check its digits, if it is odd or even.
Below is the required implementation:

SQL

--Odd and Even digits in a number
--in PL/SQL
DECLARE
  --num variable declared
  --num assign with a number
  num NUMBER := 123456;

  --len variable char declared
  len VARCHAR2(20);

  --cntvariable declared
  cnt1 NUMBER(5) := 0;
  cnt2 NUMBER(5) := 0;
BEGIN

  --for loop go from 1 to length of the number
  FOR i IN 1..Length(num)
  LOOP
    len := Substr(num, i, 1);
    IF mod(len, 2) != 0 THEN
      cnt1 := cnt1 + 1;
    ELSE
      cnt2:=cnt2+1;
    END IF;
  END LOOP;
  --end loop

  dbms_output.Put_line('Odd Digits: '
  || cnt1);
  dbms_output.Put_line('Even Digits: '
  || cnt2);
  --display result
END;
--end program

Output:

Odd Digits: 3
Even Digits: 3