Java Puzzle 7: Cookies

Aug 07, 2012

Learn how to count down with Count von Count and Cookie Monster!

cookie monster counting video

If Count has two cookies and Cookie Monster eats one, how many cookies are left?
- One cookie.

Good. If Cookie Monster eats this one cookie, what does Count have left?
- An empty hand, no cookies. And a hungry Cookie Monster.

Great. Now, for the grand finale: if Cookie Monster then eats another cookie, what does Count have in his hand?
- Minus one cookie!

If cookies were Strings, could you write the Cookie Monster? The class Count is given:

package count;

import monster.CookieMonster;

public class Count {
    public static void main(String[] args) {
        String noCookie ="cookie");
        if (noCookie.isEmpty() &amp;&amp; < noCookie.length()) {
            // The goal is to reach this line
            System.out.println("Minus one cookie!");

Edit the Cookie Monster to make it work:

package monster;

public class CookieMonster {
    public static String eat(String cookie) {
        return cookie.substring(0, cookie.length() - 6);

The usual puzzle rules apply (setAccessible() is not allowed!). If you found the solution, post it as a comment here below. These comments stay private, and become public later on the next blog post.