finished commit

MathUtilities.java

     * @return sum of `baseValue` and `difference`
     */
    public Integer add(int baseValue, int difference) {
-       return null;
+       return baseValue + difference;
    }
 
    /**
     * @return sum of `baseValue` and `difference`
     */
    public Long add(long baseValue, long difference) {
-       return null;
+       return baseValue + difference;
    }
 
    /**
     * @return sum of `baseValue` and `difference`
     */
    public Short add(short baseValue, short difference) {
-       return null;
+       return (short)(baseValue + difference);
    }
 
    /**
     * @return sum of `baseValue` and `difference`
     */
    public Byte add(byte baseValue, byte difference) {
-       return null;
+       return (byte)(baseValue + difference);
    }
 
    /**
     * @return sum of `baseValue` and `difference`
     */
    public Float add(float baseValue, float difference) {
-       return null;
+       return (float)(baseValue + difference);
    }
 
    /**
     * @return sum of `baseValue` and `difference`
     */
    public Double add(double baseValue, double difference) {
-       return null;
+       return (double)(baseValue + difference);
    }
 
    /**
     * @return difference between `baseValue` and `difference`
     */
    public Integer subtract(int baseValue, int difference) {
-       return null;
+       return baseValue - difference;
    }
 
    /**
     * @return difference between `baseValue` and `difference`
     */
    public Long subtract(long baseValue, long difference) {
-       return null;
+       return baseValue - difference;
    }
 
    /**
     * @return difference between `baseValue` and `difference`
     */
    public Short subtract(short baseValue, short difference) {
-       return null;
+       return (short)(baseValue - difference);
    }
 
    /**
     * @return difference between `baseValue` and `difference`
     */
    public Byte subtract(byte baseValue, byte difference) {
-       return null;
+       return (byte)(baseValue - difference);
    }
 
    /**
     * @return difference between `baseValue` and `difference`
     */
    public Float subtract(float baseValue, float difference) {
-       return null;
+       return (float)(baseValue - difference);
    }
 
    /**
     * @return difference between `baseValue` and `difference`
     */
    public Double subtract(double baseValue, double difference) {
-       return null;
+       return (double)(baseValue - difference);
    }
 
 
     * @return division of `dividend` by `divisor
     */
    public Integer divide(int dividend, int divisor) {
-       return null;
+       return dividend / divisor;
    }
 
    /**
     * @return division of `dividend` by `divisor
     */
    public Long divide(long dividend, long divisor) {
-       return null;
+       return dividend / divisor;
    }
 
    /**
     * @return division of `dividend` by `divisor
     */
    public Short divide(short dividend, short divisor) {
-       return null;
+       return (short)(dividend / divisor);
    }
 
    /**
     * @return division of `dividend` by `divisor
     */
    public Byte divide(byte dividend, byte divisor) {
-       return null;
+       return (byte)(dividend/divisor);
    }
 
    /**
     * @return division of `dividend` by `divisor
     */
    public Float divide(float dividend, float divisor) {
-       return null;
+       return (float)(dividend/divisor);
    }
 
    /**
     * @return division of `dividend` by `divisor
     */
    public Double divide(double dividend, double divisor) {
-       return null;
+       return (double)(dividend/divisor);
    }
 
 
     * @return product of `multiplicand` by `multiplier`
     */
    public Integer multiply(int multiplicand, int multiplier) {
-       return null;
+       return multiplicand * multiplier;
    }
 
    /**
     * @return product of `multiplicand` by `multiplier`
     */
    public Long multiply(long multiplicand, long multiplier) {
-       return null;
+       return multiplicand * multiplier;
    }
 
    /**
     * @return product of `multiplicand` by `multiplier`
     */
    public Short multiply(short multiplicand, short multiplier) {
-       return null;
+       return (short)(multiplicand * multiplier);
    }
    /**
     * @param multiplicand value to be multiplied
     * @return product of `multiplicand` by `multiplier`
     */
    public Byte multiply(byte multiplicand, byte multiplier) {
-       return null;
+       return (byte)(multiplicand * multiplier);
    }
 
    /**
     * @return product of `multiplicand` by `multiplier`
     */
    public Float multiply(float multiplicand, float multiplier) {
-       return null;
+       return (float)(multiplicand * multiplier);
    }
 
    /**
     * @return product of `multiplicand` by `multiplier`
     */
    public Double multiply(double multiplicand, double multiplier) {
-       return null;
+       return (double)(multiplicand * multiplier);
    }
 
 
      * @return true
     */
    public Boolean returnTrue() {
-       return null;
+       return true;
    }
 
    /**
     * @return false
     */
    public Boolean returnFalse() {
-       return null;
+       return false;
    }
 
 }

PredicateUtilities.java

     * @return true if `x` is greater than `y`
     */
    public Boolean isGreaterThan(int x, int y) {
-       return null;
-   }
+       if (x > y) {
+           return true;
+        }else
+        {return false;
+        }
+   
+}
 
    /**
     * @param x
     * @return true if `x` is less than `y`
     */
    public Boolean isLessThan(int x, int y) {
-       return null;
+       if (x < y) {
+           return true;}
+           else{
+               return false;}
    }
 
    /**
     * @return true if `x` is greater than or equal to `y`
     */
    public Boolean isGreaterThanOrEqualTo(int x, int y) {
-       return null;
+       if (x >= y) {
+           return true;
+        }else{
+            return false;
+        }
    }
 
    /**
     * @return true if `x` is less than or equal to `y`
     */
    public Boolean isLessThanOrEqualTo(int x, int y) {
-       return null;
+       if (x <= y) {
+           return true;
+        }else{
+            return false;
+        }
    }
 }

StringUtilities.java

      * @return `Hello World` as a string
      */
     public String getHelloWorld() {
-        return null;
+        String getHelloWorld = "Hello World";
+        return getHelloWorld;
     }
 
     /**
      * @return the concatenation of two strings, `firstSegment`, and `secondSegment`
      */
     public String concatenation(String firstSegment, String secondSegment){
-        return null;
+        String firstAndSecond = firstSegment + secondSegment;
+        return firstAndSecond;
     }
 
     /**
      * @return the concatenation of an integer, `firstSegment`, and a String, `secondSegment`
      */
     public String concatenation(int firstSegment, String secondSegment){
-        return null;
+        String newString = firstSegment + secondSegment;
+        return newString;
     }
 
     /**
      * @return the first 3 characters of `input`
      */
     public String getPrefix(String input){
-        return null;
+        String firstThree = input.substring(0, 3);
+        return firstThree;
     }
 
     /**
      * @return the last 3 characters of `input`
      */
     public String getSuffix(String input){
-        return null;
+        String lastThree = input.substring(input.length() - 3, input.length());
+        return lastThree;
     }
 
     /**
      * @return the equivalence of two strings, `inputValue` and `comparableValue`
      */
     public Boolean compareTwoStrings(String inputValue, String comparableValue){
-        return null;
+        String inputValue1 = inputValue;
+        String comparableValue1 = comparableValue;
+        return inputValue1.equals(comparableValue);
     }
 
     /**
      * @param inputValue the value input from user
      * @return the middle character of `inputValue`
      */
-    public Character getMiddleCharacter(String inputValue){
-        return null;
+    public Character getMiddleCharacter(String inputValue)
+    {
+       int mid = inputValue.length() / 2;
+       char middleChar = inputValue.charAt(mid);
+       
+       if (inputValue.length() % 2 == 0){
+           middleChar = inputValue.charAt(mid - 1);
+        }
+       return middleChar;
+    
     }
 
     /**
      * @return the first sequence of characters
      */
     public String getFirstWord(String spaceDelimitedString){
-        return null;
+        int a = spaceDelimitedString.indexOf(" ");
+        String firstWord = spaceDelimitedString.substring(0, a);
+        return firstWord;
     }
 
     /**
      * @return the second word of a string delimited by spaces.
      */
     public String getSecondWord(String spaceDelimitedString){
-        return null;
+        int start = spaceDelimitedString.indexOf(" ") + 1;
+        int end = spaceDelimitedString.indexOf(" ", start);
+        
+        if (end == -1) {
+            end = spaceDelimitedString.length();
+        }
+        String secondWord = spaceDelimitedString.substring(start, end);
+        return secondWord;
     }
 
     /**
      * @return an identical string with characters in reverse order.
      */
     public String reverse(String stringToReverse){
-        return null;
+        if (stringToReverse == null || stringToReverse.isEmpty()) {
+            return stringToReverse;
+        }
+        String reversed = "";
+        for(int i = stringToReverse.length() - 1; i >= 0; i--) {
+            reversed = reversed + stringToReverse.charAt(i);
+        }
+        return reversed;
     }
 
     /**
      * @return an identical string with spaces removed.
      */
     public String removeWhitespace(String input){
-        return null;
+        String newTrim = input.replaceAll("\\s","");
+        return newTrim;
     }
 
     /**
      * @return an identical string with spaces in the front and end removed.
      */
     public String trim(String input){
-        return null;
+        String trimmedWord = input.trim();
+        return trimmedWord;
     }
 }