Completed

MathUtilities.java

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

PredicateUtilities.java

- 
 
 /**
  * Created by dan on 6/14/17.
      * @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;
+        }
     }
 
     /**
      * @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

- 
 
 /**
  * Created by dan on 6/14/17.
      * @return `Hello World` as a string
      */
     public static String getHelloWorld() {
-        return null;
+        return "Hello Word";
     }
 
     /**
      * @return the concatenation of two strings, `firstSegment`, and `secondSegment`
      */
     public static String concatenation(String firstSegment, String secondSegment){
-        return null;
+        return firstSegment + secondSegment;
     }
 
     /**
      * @return the concatenation of an integer, `firstSegment`, and a String, `secondSegment`
      */
     public static String concatenation(int firstSegment, String secondSegment){
-        return null;
+        return firstSegment+secondSegment;
     }
 
     /**
      * @return the first 3 characters of `input`
      */
     public static String getPrefix(String input){
-        return null;
+        return input.substring(3);
     }
 
     /**
      * @return the last 3 characters of `input`
      */
     public static String getSuffix(String input){
-        return null;
+        return input.substring(input.length()-4);
     }
 
     /**
      * @return the equivalence of two strings, `inputValue` and `comparableValue`
      */
     public static Boolean compareTwoStrings(String inputValue, String comparableValue){
-        return null;
+        boolean result;
+        result = inputValue == comparableValue ? true : false;
+        return result;
     }
 
     /**
      * @return the middle character of `inputValue`
      */
     public static Character getMiddleCharacter(String inputValue){
-        return null;
+        int midpoint;
+
+        if(inputValue.length()%2!=0){
+            midpoint = (inputValue.length()-1)/2;
+        } else {
+            midpoint = (inputValue.length()/2)-1;
+        }
+
+        return inputValue.charAt(midpoint);
     }
 
     /**
      * @return the first sequence of characters
      */
     public static String getFirstWord(String spaceDelimitedString){
-        return null;
+        String word = spaceDelimitedString;
+        int delim = word.indexOf(' ');
+        return word.substring(0,delim);
     }
 
     /**
      * @return the second word of a string delimited by spaces.
      */
     public static String getSecondWord(String spaceDelimitedString){
-        return null;
+        String word = spaceDelimitedString;
+        int delim = word.indexOf(' ');
+        return word.substring(delim+1);
     }
 
     /**
      * @return an identical string with characters in reverse order.
      */
     public static String reverse(String stringToReverse){
-        return null;
+        StringBuilder builder = new StringBuilder();
+        String word = stringToReverse;
+  
+        for (int i = word.length()-1; i>=0; i--){
+            builder.append(word.charAt(i));
+        }
+        
+        String result = builder.toString();
+        System.out.println(result);
+        return result;
     }
 }

ZipcodeRocks.ctxt

+#BlueJ class context
+comment0.target=ZipcodeRocks
+comment0.text=\n\ Write\ a\ description\ of\ class\ ZipcodeRocks\ here.\n\n\ @author\ (your\ name)\n\ @version\ (a\ version\ number\ or\ a\ date)\n
+comment1.params=args
+comment1.target=void\ main(java.lang.String[])
+numComments=2

ZipcodeRocks.java

+    
+    /**
+     * Write a description of class ZipcodeRocks here.
+     *
+     * @author (your name)
+     * @version (a version number or a date)
+     */
+    public class ZipcodeRocks
+    {
+    public static void main(String[] args){
+        System.out.println("Zipcode Rocks!");
+    }
+    
+}

package.bluej

 #BlueJ package file
-editor.fx.0.height=0
-editor.fx.0.width=0
-editor.fx.0.x=0
-editor.fx.0.y=0
+editor.fx.0.height=717
+editor.fx.0.width=800
+editor.fx.0.x=-270
+editor.fx.0.y=-823
 objectbench.height=129
 objectbench.width=1171
 package.divider.horizontal=0.6
 package.divider.vertical=0.7490774907749077
 package.editor.height=399
 package.editor.width=1069
-package.editor.x=59
-package.editor.y=63
+package.editor.x=367
+package.editor.y=-709
 package.frame.height=600
 package.frame.width=1195
 package.numDependencies=0
-package.numTargets=6
+package.numTargets=7
 package.showExtends=true
 package.showUses=true
 project.charset=UTF-8
 target5.x=260
 target5.y=50
 target6.height=50
-target6.name=MathUtilitiesTest
+target6.name=ZipcodeRocks
 target6.showInterface=false
-target6.type=UnitTestTargetJunit4
-target6.width=130
-target6.x=50
-target6.y=90
+target6.type=ClassTarget
+target6.width=110
+target6.x=70
+target6.y=10
+target7.height=50
+target7.name=MathUtilitiesTest
+target7.showInterface=false
+target7.type=UnitTestTargetJunit4
+target7.width=130
+target7.x=50
+target7.y=90