completed

LoopFun.java

@@ -1,40 +1,67 @@
 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 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=1; i<=number;++i ) {
+            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) {
-          return null;
-      }
+    /**
+     * 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[] acronym = phrase.split(" ");
+        String newStr = " ";
+        for (int i = 0; i < acronym.length; i++) {
+            String s = acronym[i];
+            newStr += s.charAt(0);          
+        }
+        return newStr.replace(" ","").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) {
-          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) {
+        char[] arr = new char[word.length()];
+
+        for (int i = 0; i < arr.length; i++) {
+            if(word.charAt(i) == 'x'){
+                arr[i] = 'a';
+            } else if (word.charAt(i) == 'y'){
+                arr[i] = 'b';
+            } else if (word.charAt(i) == 'z'){
+                arr[i] = 'c';
+            }else {
+                arr[i] = (char) (word.charAt(i) + 3);
+            }
+        }   
+           
+        
+        String result = new String(arr);
+        return result;
+    
+}
 }

MathUtilities.java

@@ -6,7 +6,7 @@ public class MathUtilities{
    * @return the sum of the two numbers
    */
   public int add(int num1, int num2){
-      return -1;
+      return num1 + num2;
   }
 
   /**
@@ -16,7 +16,7 @@ public class MathUtilities{
    * @return the sum of the two numbers
    */
   public double add(double num1, double num2){
-      return -1;
+      return num1 + num2;
   }
 
   /**
@@ -25,7 +25,7 @@ public class MathUtilities{
    * @return the half of the number in double
    */
   public double half(int number) {
-      return -1;
+      return number / (double) 2;
   }
 
   /**
@@ -34,7 +34,7 @@ public class MathUtilities{
    * @return true if the number is odd, false if it is even
    */
   public boolean isOdd(int number){
-      return false;
+      return number % 2 == 0 ? false : true;
   }
 
 
@@ -44,7 +44,7 @@ public class MathUtilities{
    * @return the result of the number multiply by itself
    */
   public int square(int number) {
-      return -1;
+      return number * number;
   }
 
 }

StringUtilities.java

@@ -1,13 +1,16 @@
 public class StringUtilities {
-   public Character getMiddleCharacter(String word){
-       return null;
-   }
-   
-   public String removeCharacter(String value, char charToRemove){
-     return null;  
-   }
-   
-   public String getLastWord(String value) {
-       return null;
-   }
+    public Character getMiddleCharacter(String word){
+        char midLetter;     
+        return midLetter =  word.charAt(word.length() / 2);
+        
+    }  
+
+    public String removeCharacter(String value, char charToRemove){
+        String result = value.replace(Character.toString(charToRemove), "");
+        return result;
+    }
+
+    public String getLastWord(String value) {
+        return value.substring(value.lastIndexOf(" ")+1);
+    }
 }