Question

using RECURSIVE Functions in Java, create a public static String doubleLetters (String word)

For ex) that returns “one” as “oonnee”

Answer 1

import java.util.Scanner;

public class DoubleLetters {

    public static String doubleLetters(String word) {
        if (word.isEmpty()) {
            return "";
        } else {
            return "" + word.charAt(0) + word.charAt(0) + doubleLetters(word.substring(1));
        }
    }

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