How do you count the vowels in Java using Recursion ?

This programs counts the vowels present in the given string using the recurions.

Program to count the vowels using Recurions:

public static void main(String[] args){
        String str = "NgDevelOper.com";
        System.out.println(countVowels(str, str.length()));
    }

    private static int countVowels(String str, int length) {
        if(length ==1){
            if (isVowel(str.charAt(length-1))) {
                return 1;
            }else {
                return 0;
            }
        }
        return (countVowels(str, length-1)) + (isVowel(str.charAt(length-1)) ? 1 : 0);
    }

    private static boolean isVowel(char charAt) {
            if(charAt == 'a' || charAt == 'e' || charAt == 'i' || charAt == 'o' || charAt == 'u' || charAt == 'A' || charAt == 'E' || charAt == 'I' || charAt == 'O' || charAt == 'U')
            return true;
            return false;
    }

Output:

Input: NgDevelOper.com

5