Can you write code without using Iterator to count characters in a string?

Q. Write a sample code that will count the number of "Z"s in a given text? Show both iterative and recursive approaches?
A.

Iterative method:

public class Iteration {

    public int countA(String input) {

        if (input == null || input.length( ) == 0) {

            return 0;

        }

        int count = 0;

        for (int i = 0; i < input.length( ); i++) {

            if(input.substring(i, i+1).equals("Z")){

                count++;

            }

        }

        return count;

    }

    public static void main(String[ ] args) {

          System.out.println(new Iteration( ).countA("ZZZ"));     // Ans.3

    }

} 







Recursive method:




public class RecursiveCall {

    public int countA(String input) {

        

        // exit condition – recursive calls must have an exit condition

        if (input == null || input.length( ) == 0) {

            return 0;

        }

        int count = 0;

          

        //check first character of the input

        if (input.substring(0, 1).equals("Z")) {

            count = 1;

        }

         

        //recursive call to evaluate rest of the input

        //(i.e.  2nd character onwards)

        return count + countA(input.substring(1));

    }

    public static void main(String[ ] args) {

        System.out.println(new RecursiveCall( ).countA("ZZZ"));    // Ans. 3

    }

}