Implemented Math Utilities, few methods in StringUtilities and LoopFun

LoopFun.java

        * @return the factorial of the number
        */
       public int factorial(int number){
-          return -1;
-      }
+          int sum=0;
+          for(int i=1;i<=number;i++)
+          { 
+              int fact=i*number;
+               sum=sum+fact;
+              
+          
+      }return sum;
+    }
 
       /**
        * Given a phrase, get the acronym of that phrase. Acronym is the combination of
        * @return Upper case string of the first letter of each word
        */
       public String acronym(String phrase) {
+          phrase.trim();
+          int str=phrase.length();
+          char ch;
+          
+          
+          
+          
+          
+          
           return null;
       }
 
        * @return the encrypted string by shifting each character by three character
        */
       public String encrypt(String word) {
-          return null;
+          String str=word.replace('a','d');
+          
+          
+          return str;
       }
 }

MathUtilities.java

+
+
+
+
 public class MathUtilities{
   /**
    * Add two number together
    * @return the sum of the two numbers
    */
   public int add(int num1, int num2){
-      return -1;
+      int sum=num1+num2;
+      return sum;
   }
 
   /**
    * @return the sum of the two numbers
    */
   public double add(double num1, double num2){
-      return -1;
+      return num1+num2;
   }
 
   /**
    * @return the half of the number in double
    */
   public double half(int number) {
-      return -1;
+     double val=(double)number/2;
+      return val;
   }
 
   /**
    * @return true if the number is odd, false if it is even
    */
   public boolean isOdd(int number){
+      if(number%2==1)
+      {
+      return true;
+    }
+      else
+      {
       return false;
+    }
   }
 
 
    * @return the result of the number multiply by itself
    */
   public int square(int number) {
-      return -1;
+      return number*number;
   }
 
 }

StringUtilities.java

+ //import java.utils.*;
 public class StringUtilities {
    public Character getMiddleCharacter(String word){
-       return null;
-   }
+       int  n= word.length();
+       char ch;
+       int val=n%2;
+       int i=0;
+       if(val== 0)
+       {  
+          i =n/2;
+          ch=word.charAt(i);
+           //System.out.println(val);
+           return ch;
+          
+        }
+          else
+          {
+          i=(int)Math.floor(n/2);
+          ch= word.charAt(i -1);
+          return ch;
+        }
+    }    
+       
+   
+
    
    public String removeCharacter(String value, char charToRemove){
-     return null;  
-   }
+       int n=value.length();
+       for(int i=0;i<n;i++)
+       {
+           
+        }
+       
+    
+    
+   return null;
+}
    
    public String getLastWord(String value) {
        return null;