updated

src/main/java/rocks/zipcode/io/quiz4/collections/ComparableTreeSet.java

@@ -7,12 +7,13 @@ import java.util.TreeSet;
  */
 public class ComparableTreeSet<_> {
     public ComparableTreeSet(_... arr) {
-    }
 
+    }
 
     public ComparableTreeSet() {
     }
 
     public Integer compareTo(ComparableTreeSet<_> o) {
+        return null;
     }
 }

src/main/java/rocks/zipcode/io/quiz4/collections/SimpleStringGroup.java

@@ -1,36 +1,50 @@
 package rocks.zipcode.io.quiz4.collections;
 
+import com.sun.tools.javac.util.List;
+
+import java.util.*;
+import java.util.function.Consumer;
+
 /**
  * @author leon on 11/12/2018.
  */
-public class SimpleStringGroup {
+public class SimpleStringGroup implements Iterable{
+
+    ArrayList<String> simpleString = new ArrayList<>();
 
-    String simpleString;
 
     public SimpleStringGroup() {
-        throw new UnsupportedOperationException("Method not yet implemented");
     }
 
     public Integer count() {
-        return simpleString.length();
+        return simpleString.size();
     }
 
     public void insert(String string) {
-        simpleString = string;
+        simpleString.add(string);
     }
 
     public Boolean has(String valueToInsert) {
+        return this.contains(valueToInsert);
+    }
+
+    private Boolean contains(String valueToInsert) {
         return simpleString.contains(valueToInsert);
     }
 
     public String fetch(int indexOfValue) {
-        return null;
+       return simpleString.get(indexOfValue);
     }
 
     public void delete(String valueToInsert) {
+        simpleString.remove(valueToInsert);
     }
 
     public void clear() {
+        simpleString.removeAll(simpleString);
+    }
 
+    public Iterator<String> iterator() {
+        return simpleString.iterator();
     }
 }

src/main/java/rocks/zipcode/io/quiz4/collections/ZipCodeWilmington.java

@@ -2,23 +2,37 @@ package rocks.zipcode.io.quiz4.collections;
 
 import rocks.zipcode.io.quiz4.objectorientation.Student;
 
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.Map;
+import java.util.TreeMap;
 
 /**
  * @author leon on 11/12/2018.
  */
 public class ZipCodeWilmington {
+
+    ArrayList<Student> zipCodeWilmington = new ArrayList<Student>();
+
     public void enroll(Student student) {
+        zipCodeWilmington.add(student);
     }
 
     public Boolean isEnrolled(Student student) {
-        return null;
+        return zipCodeWilmington.contains(student);
     }
 
     public void lecture(double numberOfHours) {
+        for(Student s: zipCodeWilmington){
+            s.learn(numberOfHours);
+        }
     }
 
     public Map<Student, Double> getStudyMap() {
-        return null;
+        HashMap<Student, Double> studyMap = new HashMap<>();
+        for(Student s: zipCodeWilmington){
+            studyMap.put(s, s.getTotalStudyTime());
+        }
+        return studyMap;
     }
 }

src/main/java/rocks/zipcode/io/quiz4/generics/GenericUtils.java

@@ -16,3 +16,4 @@ public class GenericUtils {
         return powerSet(new TreeSet<>(Arrays.asList(originalSet)));
     }
 }
+

src/main/java/rocks/zipcode/io/quiz4/generics/Group.java

@@ -1,37 +1,53 @@
 package rocks.zipcode.io.quiz4.generics;
 
+import java.util.ArrayList;
 import java.util.Iterator;
 
 /**
  * @author leon on 18/12/2018.
  */
-public class Group<_> {
+public class Group<_> implements Iterable{
+
+    ArrayList<_> group = new ArrayList<_>();
+
+    public Group(ArrayList<_> group) {
+        this.group = group;
+    }
+
     public Group() {
-        throw new UnsupportedOperationException("Method not yet implemented");
     }
 
     public Integer count() {
-        return null;
+        return group.size();
     }
 
     public void insert(_ value) {
+        group.add(value);
     }
 
     public Boolean has(_ value) {
-        return null;
+        return group.contains(value);
     }
 
     public _ fetch(int indexOfValue) {
-        return null;
+        return group.get(indexOfValue);
     }
 
     public void delete(_ value) {
+        group.remove(value);
     }
 
     public void clear() {
+        group.removeAll(group);
     }
 
     public Iterator<_> iterator() {
-        return null;
+        return group.iterator();
     }
+
+    @Override
+    public String toString(){
+        return group.toString();
+    }
+
 }

src/main/java/rocks/zipcode/io/quiz4/objectorientation/PalindromeObject.java

@@ -4,7 +4,11 @@ package rocks.zipcode.io.quiz4.objectorientation;
  * @author leon on 18/12/2018.
  */
 public class PalindromeObject {
+
+    String input;
+
     public PalindromeObject(String input) {
+        this.input = input;
     }
 
     public String[] getAllPalindromes(){

src/main/java/rocks/zipcode/io/quiz4/objectorientation/StringAssembler.java

@@ -4,11 +4,16 @@ package rocks.zipcode.io.quiz4.objectorientation;
  * @author leon on 11/12/2018.
  */
 public class StringAssembler {
+
+    String stringAssembler;
+    Character delimeter;
+
     public StringAssembler(Character delimeter) {
+        this.delimeter = delimeter;
     }
 
     public StringAssembler append(String str) {
-        return null;
+
     }
 
     public String assemble() {

src/main/java/rocks/zipcode/io/quiz4/objectorientation/StringEvaluatorObject.java

@@ -4,7 +4,11 @@ package rocks.zipcode.io.quiz4.objectorientation;
  * @author leon on 19/12/2018.
  */
 public class StringEvaluatorObject {
+
+    String str;
+
     public StringEvaluatorObject(String str) {
+        this.str = str;
     }
 
     public String[] getAllPrefixes() {

src/main/java/rocks/zipcode/io/quiz4/objectorientation/Student.java

@@ -4,17 +4,33 @@ package rocks.zipcode.io.quiz4.objectorientation;
  * @author leon on 11/12/2018.
  */
 public class Student {
-    public Student() {
-        this(null);
+
+    public Student(Integer id, Double amountOfHours) {
+        this.id = id;
+        this.amountOfHours = amountOfHours;
+    }
+
+    Integer id = 0;
+    Double amountOfHours = 0.0;
+
+
+
+    public Student(double amountOfHours) {
+        this.amountOfHours = amountOfHours;
+    }
+
+    public Student(){
     }
 
     public Student(Integer id) {
+        this.id = id;
     }
 
     public void learn(Double amountOfHours) {
+        this.amountOfHours += amountOfHours;
     }
 
     public Double getTotalStudyTime() {
-        return null;
+        return amountOfHours;
     }
 }