Question

Problem Statement
Write a recursive method, vowels, that returns the number of vowels in a string. Also, write a program to test your method in JAVA

Answer 1

import java.util.Scanner;

public class CountVowelsRec {
    public static int vowels(String s){
        if(s==null || s.length()==0){
            return 0;
        }
        else{
            char ch = s.charAt(0);
            if(ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u' || ch == 'A' || ch == 'E' || ch == 'I' || ch == 'O' || ch == 'U'){
                return 1+vowels(s.substring(1));
            }
            else{
                return vowels(s.substring(1));
            }
        }
    }

    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        System.out.print("Enter string: ");
        String s = scan.nextLine();
        System.out.println(vowels(s));
    }
}