Elliott First Quiz

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 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 sum = 1;
+
+        for(int i = 1; i <= number; i++){
+            sum *= i;
+        }
+        return sum;
+    }
+
+    /**
+     * 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[] phraseAcro = phrase.split(" ");
+        StringBuilder sb = new StringBuilder();
+
+        for(int i=0; i < phraseAcro.length; i++){
+            sb.append(phraseAcro[i].charAt(0));
+        }
+
+        String x = sb.toString().toUpperCase();
+
+        return x;
+    }
+
+    /**
+     * 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 shifted = "";
+        for (int i = 0; i < word.length(); i++)
+        {
+            if (isLetter(word.charAt(i)))
+            {
+                shifted = shifted + shift(word.charAt(i), shift);
+            }
+            else
+            {
+                shifted = shifted + original.charAt(i);
+            }
+        }
+
+        return shifted;
+    }
 }

MathUtilities.java

@@ -6,7 +6,9 @@ public class MathUtilities{
    * @return the sum of the two numbers
    */
   public int add(int num1, int num2){
-      return -1;
+      int sum = num1 + num2;
+      
+      return sum;
   }
 
   /**
@@ -16,7 +18,9 @@ public class MathUtilities{
    * @return the sum of the two numbers
    */
   public double add(double num1, double num2){
-      return -1;
+      double sum = num1 + num2;
+      
+      return sum;
   }
 
   /**
@@ -25,7 +29,9 @@ public class MathUtilities{
    * @return the half of the number in double
    */
   public double half(int number) {
-      return -1;
+      double sum = (double) number / 2;
+      
+      return sum;
   }
 
   /**
@@ -34,7 +40,11 @@ public class MathUtilities{
    * @return true if the number is odd, false if it is even
    */
   public boolean isOdd(int number){
-      return false;
+    if(number % 2 != 0){
+        return true;
+    } else {
+        return false;
+    }
   }
 
 
@@ -44,7 +54,9 @@ public class MathUtilities{
    * @return the result of the number multiply by itself
    */
   public int square(int number) {
-      return -1;
+      int result = number * number;
+      
+      return result;
   }
 
 }

StringUtilities.java

@@ -1,13 +1,29 @@
 public class StringUtilities {
    public Character getMiddleCharacter(String word){
-       return null;
+       int position;
+       int length;
+       if(word.length() % 2 == 0){
+        position = word.length() / 2;
+        char c = word.charAt(position);
+        } else {
+        position = word.length() /2;
+        char c = word.charAt(position);
+        }
+       char c = word.charAt(position);
+       return c;
    }
    
    public String removeCharacter(String value, char charToRemove){
-     return null;  
+       String x = Character.toString(charToRemove);
+       String y = value.replaceAll(x, "");
+       
+       return y;  
    }
    
    public String getLastWord(String value) {
-       return null;
+       
+       String everythingButLast = value.substring(value.lastIndexOf(" ") + 1);
+       
+       return everythingButLast;
    }
 }