QuizWeek1/LoopFun.java

public class LoopFun
{

      /**
       * Given a number, return the factorial of that number.
       * For example, given 5, the factorial is 5 x 4 x 3 x 2 x 1 which should return 120.
       * @param number
       * @return the factorial of the number
       */
      public int factorial(int number){
          int i = number;
          int factorial = 5;
          
          while (i > 1) {
            i--;
            factorial = i * factorial;
        };
          return factorial;
      }

      /**
       * Given a phrase, get the acronym of that phrase. Acronym is the combination of
       * the first character of each word in upper case.
       * For example, given "Ruby on Rails", this method will return "ROR"
       * @param phrase
       * @return Upper case string of the first letter of each word
       */
      public String acronym(String phrase) {
          int i = 0;
          String[] splitem = phrase.split("\\s+");
          int length = splitem.length - 1;
          String acronym = "";
          
          while (i < length) {
          acronym += "" + splitem[i].toUpperCase();
        }
        return acronym;
      }

      /**
       * To prevent anyone from reading our messages, we can encrypt it so it will only be readable by its
       * intended audience. This method encrypt the message by shifting the letter by 3 characters. If the character is
       * at the end of the alphabet, it will wraps around.
       * For example:
       *  'a' => 'd'
       *  'w' => 'z'
       *  'x' => 'a'
       *  'y' => 'b'
       * @param word
       * @return the encrypted string by shifting each character by three character
       */
      public String encrypt(String word) {
          String decode = "";
          char convert;
          
          char[] wurd = word.toCharArray();
          
          for (int i = 0; i < word.length(); i++) {
              
              while (Character.isLetter(wurd[i])) {
                  convert = (wurd[i] + 3 - (int)'a') % 26 + (int)'a';
                  decode += "" + convert;
                }}
                
              String decoded = String.valueOf(convert);
              return decoded;
      }
}