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 total = 0;
          for (int i=1;i<=number;i++) {
              total = total * i;
              i++;
            }
          return total;
      }

      /**
       * 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) {
        StringBuilder newStr = new StringBuilder();
        String[] array = phrase.split(" ");
            for (int i=0;i<array.length;i++){
                phrase = array[i].substring(0, 1).toUpperCase();
                newStr.append(phrase);
            }
        return newStr.toString();
      }

      /**
       * 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++) {
          if (((char)(word.charAt(i) + 3)  > 'Z' &&
                         word.charAt(i) <= 'Z') 
                    || ((char)(word.charAt(i) + 3)  > 'z' 
                        && word.charAt(i) <= 'z')){
                            encrypted = encrypted + (char)(word.charAt(i) + 3 - 26);	
				}
				else 
				{encrypted = encrypted + (char)(word.charAt(i) + 3);
				}
				encrypted = encrypted + word.charAt(i);
}
			                
            return encrypted;                  
      }
    }