QuizWeek1/LoopFun.java

package QuizWeek1;

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 result = 1;
        if (number == 0){
            result = 1;
        } else {
            for (int i = 1; i <= number; i++){
                result *= i;

            }

        }
        return result;
    }

    /**
     * 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 newPhrase = phrase.toUpperCase();
        
        char[] charArray = newPhrase.toCharArray();
        String firstLet = Character.toString(charArray[0]);
        //System.out.println(firstLet);
        
        for (int i = 1; i < charArray.length; i++){
            if (charArray[i] == ' '){
                System.out.println(charArray[i]);
                firstLet += (charArray[i]+1);
                System.out.println(firstLet);
            }
        }

        
        return firstLet;
    }

    /**
     * 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) {
        // ASCII Table - a = 97, z = 122

        char[] charArray = word.toCharArray();
        for (int i = 0; i < charArray.length; i++){
            (int)charArray[i] += 3;
            if ((int)charArray[i] > 119){
                (int)charArray[i] -= 23;
            }
        }

        return null;
    }
}