Question

• Prompt the user for a text string.
• Print each letter of the string to the console in reverse order.
• When finished print “I’m done” on a new line.
• Do not use any looping constructs to accomplish this.
  • This means no DO, While or For loops

In Java

For example, if the user were to input “Hello”. The out put would be :

olleH

I’m done.

Answer 1

import java.util.Scanner;

public class ReverseStrings {

    public static void printReverse(String s) {
        if (s.length() == 0) {
            System.out.println("\nI'm done.");
        } else {
            System.out.print(s.charAt(s.length() - 1));
            printReverse(s.substring(0, s.length() - 1));
        }
    }

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