MathUtilities.java

      * @return sum of `baseValue` and `difference`
      */
     public Integer add(int baseValue, int difference) {
-        return null;
+        int sum = baseValue + difference;
+      
+        return sum;
     }
 
     /**
      * @return sum of `baseValue` and `difference`
      */
     public Long add(long baseValue, long difference) {
-        return null;
+        
+        long sum =  baseValue +  difference;
+     
+        return sum;
     }
 
     /**
      * @return sum of `baseValue` and `difference`
      */
     public Short add(short baseValue, short difference) {
-        return null;
+         int num1 = baseValue;
+         int num2 = difference;
+         int sum = (num1) + (num2);
+     
+        return (short)sum;
     }
 
     /**
      * @return sum of `baseValue` and `difference`
      */
     public Byte add(byte baseValue, byte difference) {
-        return null;
+         int num1 = baseValue;
+         int num2 = difference;
+        int sum = (num1) + (num2);
+        return (byte) sum;
     }
 
     /**
      * @return sum of `baseValue` and `difference`
      */
     public Float add(float baseValue, float difference) {
-        return null;
+        
+       float sum = baseValue + difference;
+        return sum;
     }
 
     /**
      * @return sum of `baseValue` and `difference`
      */
     public Double add(double baseValue, double difference) {
-        return null;
+        double sum = baseValue + difference;
+        return sum;
     }
 
     /**
      * @return difference between `baseValue` and `difference`
      */
     public Integer subtract(int baseValue, int difference) {
-        return null;
+         int diff = baseValue - difference;
+        return diff;
     }
 
     /**
      * @return difference between `baseValue` and `difference`
      */
     public Long subtract(long baseValue, long difference) {
-        return null;
+        long diff = baseValue - difference;
+        return diff;
     }
 
     /**
      * @return difference between `baseValue` and `difference`
      */
     public Short subtract(short baseValue, short difference) {
-        return null;
+        int num1 = baseValue;
+        int num2 = difference;
+        int diff = num1 - num2;
+       
+        return (short)diff;
+    
+        
     }
 
     /**
      * @return difference between `baseValue` and `difference`
      */
     public Byte subtract(byte baseValue, byte difference) {
-        return null;
+        int num1 = baseValue;
+         int num2 = difference;
+         int diff = (num1) - (num2);
+     
+        return (byte) diff;
+    
     }
 
     /**
      * @return difference between `baseValue` and `difference`
      */
     public Float subtract(float baseValue, float difference) {
-        return null;
+        float diff = baseValue - difference;
+        return diff;
     }
 
     /**
      * @return difference between `baseValue` and `difference`
      */
     public Double subtract(double baseValue, double difference) {
-        return null;
+        double diff = baseValue - difference;
+        return diff;
     }
 
 
      * @return division of `dividend` by `divisor
      */
     public Integer divide(int dividend, int divisor) {
-        return null;
+        int Div = dividend/divisor;
+        return Div;
     }
 
     /**
      * @return division of `dividend` by `divisor
      */
     public Long divide(long dividend, long divisor) {
-        return null;
+        long Div = dividend/divisor;
+        return Div;
     }
 
     /**
      * @return division of `dividend` by `divisor
      */
     public Short divide(short dividend, short divisor) {
-        return null;
+        int num1 = dividend;
+        int num2 = divisor;
+        int Div = dividend/divisor;
+        return (short) Div;
     }
 
     /**
      * @return division of `dividend` by `divisor
      */
     public Byte divide(byte dividend, byte divisor) {
-        return null;
+        int num1 = dividend;
+        int num2 = divisor;
+        int Div = dividend / divisor;
+        return (byte) Div;
     }
 
     /**
      * @return division of `dividend` by `divisor
      */
     public Float divide(float dividend, float divisor) {
-        return null;
+        float Div = dividend / divisor;
+        return Div;
     }
 
     /**
      * @return division of `dividend` by `divisor
      */
     public Double divide(double dividend, double divisor) {
-        return null;
+        double Div = dividend / divisor;
+        return Div;
     }
 
 
      * @return product of `multiplicand` by `multiplier`
      */
     public Integer multiply(int multiplicand, int multiplier) {
-        return null;
+        int multi = multiplicand * multiplier;
+       return multi;
+       
     }
 
     /**
      * @return product of `multiplicand` by `multiplier`
      */
     public Long multiply(long multiplicand, long multiplier) {
-        return null;
+        long multi =  multiplicand * multiplier;
+       return multi;
     }
 
     /**
      * @return product of `multiplicand` by `multiplier`
      */
     public Short multiply(short multiplicand, short multiplier) {
-        return null;
+       int num1 = multiplicand;
+       int num2 = multiplier;
+       int multi = (multiplicand) * (multiplier);
+       return  (short) multi;
     }
     /**
      * @param multiplicand value to be multiplied
      * @return product of `multiplicand` by `multiplier`
      */
     public Byte multiply(byte multiplicand, byte multiplier) {
-        return null;
+       int num1 = multiplicand;
+       int num2 = multiplier;
+       int multi = (multiplicand) * (multiplier);
+       return  (byte) multi;
     }
 
     /**
      * @return product of `multiplicand` by `multiplier`
      */
     public Float multiply(float multiplicand, float multiplier) {
-        return null;
+        float multi = multiplicand * multiplier;
+        return multi;
     }
 
     /**
      * @return product of `multiplicand` by `multiplier`
      */
     public Double multiply(double multiplicand, double multiplier) {
-        return null;
+        double multi = multiplicand * multiplier;
+        return multi;
     }
 
 
       * @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;
+        }   
+    
     }
 }

PredicateUtilitiesTest.java

         int lesserValue = 350;
 
 
-        // : When
+        // : When 
         boolean outcome = math.isGreaterThan(greaterValue, lesserValue);
 
         // : Then

StringUtilities.java

- 
 
 /**
  * Created by dan on 6/14/17.
      * @return `Hello World` as a string
      */
     public static String getHelloWorld() {
-        return null;
+        String abc = "Hello World";
+        return abc;
     }
 
     /**
      * @return the concatenation of two strings, `firstSegment`, and `secondSegment`
      */
     public static String concatenation(String firstSegment, String secondSegment){
-        return null;
+        String cat = firstSegment + secondSegment;
+        return cat;
     }
 
     /**
      * @return the concatenation of an integer, `firstSegment`, and a String, `secondSegment`
      */
     public static String concatenation(int firstSegment, String secondSegment){
-        return null;
+
+        String con = firstSegment + secondSegment;
+        return con;
     }
 
     /**
      * @return the first 3 characters of `input`
      */
     public static String getPrefix(String input){
-        return null;
+
+        String abc = input.substring(0,3);
+        return abc;
+
     }
 
     /**
      * @return the last 3 characters of `input`
      */
     public static String getSuffix(String input){
-        return null;
+        String abc = input.substring(2,5);
+        return abc;
     }
 
     /**
      * @return the equivalence of two strings, `inputValue` and `comparableValue`
      */
     public static Boolean compareTwoStrings(String inputValue, String comparableValue){
-        return null;
+        Boolean abc = inputValue.equals (comparableValue);
+        return abc;
+
     }
 
     /**
      * @return the middle character of `inputValue`
      */
     public static Character getMiddleCharacter(String inputValue){
-        return null;
+        int val = 0;
+        char mid = 0;
+
+        if (inputValue.length() %2 == 0) {
+
+            mid = inputValue.charAt (inputValue.length ()/2 -1);
+        } else{
+            mid = inputValue.charAt (inputValue.length ()/2);
+        }
+
+        return mid;
     }
 
     /**
      * @return the first sequence of characters
      */
     public static String getFirstWord(String spaceDelimitedString){
-        return null;
+
+        return spaceDelimitedString.split(" ") [0];
     }
 
     /**
      * @param spaceDelimitedString a string delimited by spaces
      * @return the second word of a string delimited by spaces.
      */
+
     public static String getSecondWord(String spaceDelimitedString){
-        return null;
+        return spaceDelimitedString.split(" ") [1];
     }
 
     /**
      * @return an identical string with characters in reverse order.
      */
     public static String reverse(String stringToReverse){
-        return null;
+        String wo = "";
+        for (int i = stringToReverse.length()-1;i >=0; i--) {
+            wo += stringToReverse.charAt(i);
+            
+        }
+        return wo;
     }
 }
+

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
+dependency1.from=PredicateUtilitiesTest
+dependency1.to=PredicateUtilities
+dependency1.type=UsesDependency
+editor.fx.0.height=709
+editor.fx.0.width=933
+editor.fx.0.x=394
+editor.fx.0.y=23
 objectbench.height=129
-objectbench.width=1171
-package.divider.horizontal=0.6
+objectbench.width=513
+package.divider.horizontal=0.6004618937644342
 package.divider.vertical=0.7490774907749077
 package.editor.height=399
-package.editor.width=1069
-package.editor.x=59
-package.editor.y=63
+package.editor.width=760
+package.editor.x=112
+package.editor.y=31
 package.frame.height=600
-package.frame.width=1195
-package.numDependencies=0
+package.frame.width=886
+package.numDependencies=1
 package.numTargets=6
 package.showExtends=true
 package.showUses=true