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 fact =1;
          for(int i=1;i<=number;i++)
            fact *=i;
          return fact;
      }

      /**
       * 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) {
          
        String ar[] = phrase.split(" ");
        phrase ="";
        for(String p : ar) {
            phrase += p.substring(0,1).toUpperCase();
        }
        //System.out.println(phrase); 
          return phrase;
      }

      /**
       * 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 encrypted = "";
         for (int i = 0; i < word.length(); i++) {
            char ch = word.charAt(i);
            if (ch != ' ') {
                ch = (char)((ch - 'a' + 3) % 26 + 'a');
            }

            encrypted += ch;
        }
          return encrypted;
      }
}