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 factorial = 1;
          for (int i = number; i >0; i--){
            factorial = factorial * i;
            }
          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) {
          String str = phrase.substring(0,1);
          for (int i =0; i < phrase.length(); i++){
            if (phrase.charAt(i) == (' ')){
            str = str + phrase.charAt(i+1);
            }
            str = str.toUpperCase(); 
          
          
        } return str;
      }

      /**
       * 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) {
          StringBuilder sB = new StringBuilder(); 
          for (int i =0; i < word.length(); i++){
            if (word.charAt(i) == 'a'){
                sB = sB.append("d");
            }else if (word.charAt(i) == 'b'){
            sB = sB.append("e");
            }else if (word.charAt(i) == 'c'){
            sB = sB.append("f");
            } else if (word.charAt(i) == 'd'){
            sB = sB.append("g");
            } else if (word.charAt(i) == 'e'){
            sB = sB.append("h");
            } else if (word.charAt(i) == 'f'){
            sB = sB.append("i");
            } else if (word.charAt(i) == 'g'){
            sB = sB.append("j");
            } else if (word.charAt(i) == 'h'){
            sB = sB.append("k");
            } else if (word.charAt(i) == 'i'){
            sB = sB.append("l");
            } else if (word.charAt(i) == 'j'){
            sB = sB.append("m");
            } else if (word.charAt(i) == 'k'){
            sB = sB.append("n");
            } else if (word.charAt(i) == 'l'){
            sB = sB.append("o");
            } else if (word.charAt(i) == 'm'){
            sB = sB.append("p");
            } else if (word.charAt(i) == 'n'){
            sB = sB.append("q");
            } else if (word.charAt(i) == 'o'){
            sB = sB.append("r");
            } else if (word.charAt(i) == 'p'){
            sB = sB.append("s");
            } else if (word.charAt(i) == 'q'){
            sB = sB.append("t");
            } else if (word.charAt(i) == 'r'){
            sB = sB.append("u");
            } else if (word.charAt(i) == 's'){
            sB = sB.append("v");
            } else if (word.charAt(i) == 't'){
            sB = sB.append("w");
            } else if (word.charAt(i) == 'u'){
            sB = sB.append("x");
            } else if (word.charAt(i) == 'v'){
            sB = sB.append("y");
            } else if (word.charAt(i) == 'w'){
            sB = sB.append("z");
            } else if (word.charAt(i) == 'x'){
            sB = sB.append("a");
            } else if (word.charAt(i) == 'y'){
            sB = sB.append("b");
            } else if (word.charAt(i) == 'z'){
            sB = sB.append("c");
            }
          
      }return sB.toString(); 
    } 
}