Curtis Cook's Quiz 1

LoopFun.java

@@ -8,7 +8,11 @@ public class LoopFun
        * @return the factorial of the number
        */
       public int factorial(int number){
-          return -1;
+          int factorial = 1;
+          for(int i = 1; i <= number; i++) {
+              factorial *= i;
+            }  
+          return factorial;
       }
 
       /**
@@ -19,7 +23,14 @@ public class LoopFun
        * @return Upper case string of the first letter of each word
        */
       public String acronym(String phrase) {
-          return null;
+          StringBuilder acronym = new StringBuilder();
+          acronym.append(phrase.charAt(0));
+          for(int i = 0; i < phrase.length(); i++){
+              if(Character.isWhitespace(phrase.charAt(i))) {
+                  acronym.append(phrase.charAt(i + 1));
+              }
+          }
+          return acronym.toString().toUpperCase();
       }
 
       /**
@@ -35,6 +46,19 @@ public class LoopFun
        * @return the encrypted string by shifting each character by three character
        */
       public String encrypt(String word) {
-          return null;
+          String alphabet = "abcdefghijklmnopqrstuvwxyz";
+
+          StringBuilder encryptedWord = new StringBuilder();
+          for(int i = 0; i < word.length(); i++) {
+              char letter = word.charAt(i);
+              int index = 0;
+              if(alphabet.indexOf(letter + 3) == -1) {
+                  index = ((alphabet.indexOf(letter) - 26) + 3);
+              } else {
+                  index = alphabet.indexOf(letter + 3);
+              }
+              encryptedWord.append(alphabet.charAt(index));
+          }
+          return encryptedWord.toString();
       }
 }

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 (double) number / 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 ? true : false;
   }
 
 
@@ -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 +1,27 @@
 public class StringUtilities {
    public Character getMiddleCharacter(String word){
-       return null;
+       int middleIndex = word.length() / 2;
+       char middleCharacter = word.charAt(middleIndex);
+       return middleCharacter;
    }
    
    public String removeCharacter(String value, char charToRemove){
-     return null;  
+       StringBuilder sb = new StringBuilder(value);
+       
+       while(sb.toString().indexOf(charToRemove) != -1) {
+           sb = sb.deleteCharAt(sb.toString().indexOf(charToRemove));
+       }       
+       return sb.toString();  
    }
    
    public String getLastWord(String value) {
-       return null;
+       String lastWord = "";
+       for(int i = value.length() - 1; i > 0; i--) {
+           if(Character.isWhitespace(value.charAt(i))) {
+               lastWord = value.substring(i + 1, value.length());
+               break;
+           }
+       }
+       return lastWord;
    }
 }