Updated methods in LoopFun, MathUtilities, and StringUtilities

LoopFun.java

@@ -1,40 +1,93 @@
 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){
-          return -1;
-      }
-
-      /**
-       * 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) {
-          return null;
-      }
-
-      /**
-       * 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) {
-          return null;
-      }
+    /**
+     * 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 counter = number;
+        for (int i = number - 1; i > 1; i --) {
+            counter = counter * i;
+        }
+
+        return counter;
+    }
+
+    /**
+     * 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 upperAcro = "";
+
+        String[] words = phrase.split(" ");
+
+        // cycle through and grab each char @ 0 and return to string
+
+        for (int i = 0; i < words.length; i++) {
+            upperAcro += Character.toString(words[i].charAt(0));
+        }
+
+        return upperAcro.toUpperCase();
+
+    }
+
+    /**
+     * 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) {
+        // encoder of full alphabet
+        String encoder = "abcdefghijklmnopqrstuvwxyz";
+        String decryptMessage = "";
+        int encodeMove = 3;
+
+        // nested for loop to check chars to chars of the string
+        for (int i = 0; i < word.length(); i++){
+            // this loop checks char @ i and compares to the encoder string
+            for (int j = 0; j < encoder.length(); j++) {
+                // cycles through encoder and finds the position in the encoder
+                // loops back to front, if j == encoder.length();
+                // j = 0
+                if (word.charAt(i) == (encoder.charAt(j))) {
+                    if (j >= 23) {
+
+                        int k = j;
+                        int end = encoder.length() - 1;
+                        // add until it hits 26, then reinitialize to -1 (for case "x"  it should be at index 0)
+                        for (int l = 0; l <= 2; l++) {
+                            if ( k == end ) {
+                                k = -1;
+                            }
+                            k ++;
+                        }
+
+                        decryptMessage += Character.toString(encoder.charAt(k));
+                    } else {
+                        decryptMessage += Character.toString(encoder.charAt(j+3));
+                    }
+                }
+            }
+
+        }
+        // if statement to wrap around
+
+        return decryptMessage;
+    }
 }

MathUtilities.java

@@ -1,50 +1,54 @@
 public class MathUtilities{
-  /**
-   * Add two number together
-   * @param num1 first number
-   * @param num2 second number
-   * @return the sum of the two numbers
-   */
-  public int add(int num1, int num2){
-      return -1;
-  }
+    /**
+     * Add two number together
+     * @param num1 first number
+     * @param num2 second number
+     * @return the sum of the two numbers
+     */
+    public int add(int num1, int num2){
+        return num1 + num2;
+    }
 
-  /**
-   * Add two number together
-   * @param num1 first number
-   * @param num2 second number
-   * @return the sum of the two numbers
-   */
-  public double add(double num1, double num2){
-      return -1;
-  }
+    /**
+     * Add two number together
+     * @param num1 first number
+     * @param num2 second number
+     * @return the sum of the two numbers
+     */
+    public double add(double num1, double num2){
+        return num1 + num2;
+    }
 
-  /**
-   * Get half the value of the number
-   * @param number the number given
-   * @return the half of the number in double
-   */
-  public double half(int number) {
-      return -1;
-  }
+    /**
+     * Get half the value of the number
+     * @param number the number given
+     * @return the half of the number in double
+     */
+    public double half(int number) {
+        double halfNum = (double) number;
+        return halfNum/2;
+    }
 
-  /**
-   * Determine if the number is odd
-   * @param number the number given
-   * @return true if the number is odd, false if it is even
-   */
-  public boolean isOdd(int number){
-      return false;
-  }
+    /**
+     * Determine if the number is odd
+     * @param number the number given
+     * @return true if the number is odd, false if it is even
+     */
+    public boolean isOdd(int number){
+        if (number % 2 == 0) {
+            return false;
+        } else {
+            return true;
+        }
+    }
 
-
-  /**
-   * Multiply the number by itself
-   * @param number the number given
-   * @return the result of the number multiply by itself
-   */
-  public int square(int number) {
-      return -1;
-  }
+    /**
+     * Multiply the number by itself
+     * @param number the number given
+     * @return the result of the number multiply by itself
+     */
+    public int square(int number) {
+        return (int) Math.pow(number, 2);
+    }
 
 }

StringUtilities.java

@@ -1,13 +1,23 @@
 public class StringUtilities {
    public Character getMiddleCharacter(String word){
-       return null;
+        int middleVal = (word.length() / 2);
+        return word.charAt(middleVal);
    }
    
    public String removeCharacter(String value, char charToRemove){
-     return null;  
+     // remove the characters in the string using replace with ""
+     
+     String newString = value.replace(Character.toString(charToRemove), "");
+     
+     return newString;  
    }
    
    public String getLastWord(String value) {
-       return null;
+       // return the last word of the string
+       // use split and return the last word of the array
+       String words = "";
+       String[] famousLastWords = value.split(" ");
+       
+       return famousLastWords[famousLastWords.length -1];
    }
 }