src/main/java/rocks/zipcode/quiz5/arrays/ArrayUtils.java

 package rocks.zipcode.quiz5.arrays;
 
+import java.util.Arrays;
+
 /**
  * @author leon on 01/01/2019.
  */
 public class ArrayUtils {
     public static String getMiddleElement(String[] values) {
-        return null;
+
+        int halfLength = values.length / 2;
+        String midElement;
+
+        if (halfLength % 2 == 0) {
+            midElement = values[halfLength];
+
+        } else {
+
+            midElement = values[halfLength];
+        }
+
+        return midElement;
     }
 
     public static String[] removeMiddleElement(String[] values) {
-        return null;
+
+        int x = (values.length - 1) / 2;
+        String[] copy = new String[x * 2];
+
+        System.arraycopy(values, 0, copy, 0, x);
+        System.arraycopy(values, values.length - x, copy, x, x);
+
+        return copy;
     }
 
     public static String getLastElement(String[] values) {
-        return null;
+
+        int endOfString = values.length - 1;
+        String lastElement;
+
+        if (endOfString % 2 == 0) {
+            lastElement = values[endOfString];
+
+        } else {
+            lastElement = values[endOfString];
+        }
+
+        return lastElement;
     }
 
     public static String[] removeLastElement(String[] values) {
-        return null;
+
+        return Arrays.copyOf(values, values.length - 1);
     }
 }

src/main/java/rocks/zipcode/quiz5/collections/Bank.java

 
 import rocks.zipcode.quiz5.objectorientation.account.BankAccount;
 
+import java.util.ArrayList;
+
+
 /**
  * @author leon on 27/12/2018.
  */
 public class Bank {
+
+    private ArrayList<BankAccount> bank = new ArrayList<>();
+
     public BankAccount removeBankAccountByIndex(Integer indexNumber) {
-        return null;
+
+        BankAccount ba = bank.get(indexNumber);
+
+        bank.remove(ba);
+        bank.remove(indexNumber);
+
+        return ba;
     }
 
     public void addBankAccount(BankAccount bankAccount) {
+
+        this.bank.add(bankAccount);
+
     }
 
     public Boolean containsBankAccount(BankAccount bankAccount) {
-        throw new UnsupportedOperationException("Method not yet implemented");
+
+        return this.bank.contains(bankAccount);
     }
 }

src/main/java/rocks/zipcode/quiz5/collections/Food.java

  */
 public class Food {
     public List<Spice> getAllSpices() {
+
         return null;
     }
 
     public <SpiceType extends Class<? extends Spice>> Map<SpiceType, Integer> getSpiceCount() {
+
         return null;
     }
 

src/main/java/rocks/zipcode/quiz5/collections/WordCounter.java

 package rocks.zipcode.quiz5.collections;
 
+import javax.swing.*;
+import java.util.HashMap;
 import java.util.Map;
 
 public class WordCounter {
     }
 
     public Map<String, Integer> getWordCountMap() {
-        return null;
+
+        String s = JOptionPane.showInputDialog("Enter any text.");
+        String[] splitString = s.split(" ");
+        Map<String, Integer> hashmap = new HashMap<>();
+
+        for (int i = 0; i < splitString.length; i++) {
+
+            if (!hashmap.containsKey(splitString[i])) {
+                hashmap.put(splitString[i], 2);
+
+            } else {
+
+                hashmap.put(splitString[i], hashmap.get(splitString[i]) + 1);
+            }
+        }
+        for (Object word : hashmap.keySet()) {
+
+            hashmap.get(word);
+        }
+        return hashmap;
+
     }
+
 }

src/main/java/rocks/zipcode/quiz5/fundamentals/Calculator.java

  */
 public class Calculator {
     public static Double squareRoot(Double value) {
-        return null;
+
+        return Math.sqrt(value);
     }
 
     public static Double square(Double value) {
-        return null;
+
+        return value * value;
     }
 
     public static Double[] squareRoots(Double... value) {
-        return null;
+
+        Double[] results = new Double[value.length];
+
+        for (int i = 0; i < value.length; i++) {
+            results[i] = Math.sqrt(value[i]);
+        }
+
+        return results;
     }
 
     public static Double[] squares(Double... values) {
-        return null;
+
+        Double[] results = new Double[values.length];
+
+        for (int i = 0; i < values.length; i++) {
+            results[i] = values[i] * values[i];
+        }
+
+        return results;
     }
 
     public static Double add(Double value1, Double value2) {
-        return null;
+
+        return value1 + value2;
     }
 
     public static Double subtract(Double value1, Double value2) {
-        return null;
+
+        return value1 - value2;
     }
 
 
     public static Double divide(Double divisor, Double dividend) {
-        return null;
+
+        return divisor / dividend;
     }
 }

src/main/java/rocks/zipcode/quiz5/fundamentals/StringUtils.java

 package rocks.zipcode.quiz5.fundamentals;
 
+import java.util.Arrays;
+
 /**
  * @author leon on 21/12/2018.
  */
 public class StringUtils {
     public static Character getMiddleCharacter(String string) {
-        return null;
+
+        int halfLength = string.length() / 2;
+        char midChar;
+
+        if (halfLength % 2 == 0) {
+
+            midChar = string.charAt(halfLength);
+
+        } else {
+
+            midChar = string.charAt(halfLength);
+        }
+
+        return midChar;
     }
 
     public static String capitalizeMiddleCharacter(String str) {
-        return null;
+
+        char[] charArray = str.toCharArray();
+
+        charArray[charArray.length / 2] = Character.toUpperCase(charArray[charArray.length / 2]);
+        String newStr = new String(charArray);
+
+        return newStr;
     }
 
     public static String lowerCaseMiddleCharacter(String str) {
-        return null;
+
+        char[] charArray = str.toCharArray();
+
+        charArray[charArray.length / 2] = Character.toLowerCase(charArray[charArray.length / 2]);
+        String newStr = new String(charArray);
+
+        return newStr;
     }
 
     public static Boolean isIsogram(String str) {
-        return null;
+
+        str = str.toLowerCase();
+        char array[] = str.toCharArray();
+        Arrays.sort(array);
+
+        for (int i = 0; i < str.length() - 1; i++) {
+
+            if (array[i] == array[i + 1])
+                return false;
+        }
+
+        return true;
     }
 
     public static Boolean hasDuplicateConsecutiveCharacters(String str) {
-        return null;
+
+        for (int i = 1; i < str.length(); i++) {
+
+            if (str.charAt(i) == str.charAt(i - 1))
+
+            return true;
+        }
+        return false;
     }
 
     public static String removeConsecutiveDuplicateCharacters(String str) {
-        return null;
+
+       StringBuilder sb = new StringBuilder();
+       String[] array = str.split("");
+       String letter = array[0];
+
+        for (int i = 1; i < array.length; i++) {
+            String nextLetter = array[i];
+
+            if(letter.equals(nextLetter)) {
+                array[i] = "";
+                array[i - 1] = "";
+
+            }else{
+
+                letter = array[i];
+            }
+        }
+
+        for(String s : array) {
+            sb.append(s);
+        }
+
+        return sb.toString();
     }
 
     public static String invertCasing(String str) {
-        return null;
+
+        char[] chars = str.toCharArray();
+
+        for (int i = 0; i < chars.length; i++) {
+            char newChars = chars[i];
+
+            if (Character.isUpperCase(newChars)) {
+
+                chars[i] = Character.toLowerCase(newChars);
+
+            } else if (Character.isLowerCase(newChars)) {
+
+                chars[i] = Character.toUpperCase(newChars);
+            }
+        }
+        return new String(chars);
     }
 }

src/main/java/rocks/zipcode/quiz5/objectorientation/Curry.java

 package rocks.zipcode.quiz5.objectorientation;
 
-public class Curry {
+public class Curry implements Spice{
 }

src/main/java/rocks/zipcode/quiz5/objectorientation/Ginger.java

 /**
  * @author leon on 27/12/2018.
  */
-public class Ginger {
+public class Ginger implements Spice{
 }

src/main/java/rocks/zipcode/quiz5/objectorientation/Pepper.java

 /**
  * @author leon on 27/12/2018.
  */
-public class Pepper {
+public class Pepper implements Spice {
 }

src/main/java/rocks/zipcode/quiz5/objectorientation/account/Account.java

 /**
  * @author leon on 30/12/2018.
  */
-public class Account extends BankAccount {
+public class Account {
+
     public Long getId() {
+
         return null;
     }
 

src/main/java/rocks/zipcode/quiz5/objectorientation/account/BankAccount.java

 /**
  * @author leon on 27/12/2018.
  */
-public class BankAccount {
+public class BankAccount extends Account implements Transactable{
+
     public void setBalance(Double val) {
+
+    }
+
+    @Override
+    public void deposit(Double amountToIncreaseBy) {
+
+    }
+
+    @Override
+    public void withdrawal(Double amountToDecreaseBy) {
+
+    }
+
+    @Override
+    public Double getBalance() {
+        return null;
     }
 }

src/main/java/rocks/zipcode/quiz5/objectorientation/account/Employee.java

 /**
  * @author leon on 30/12/2018.
  */
-public class Employee {
-    public Employee() {
-    }
+public class Employee implements Transactable, Worker {
+
 
     public Employee(BankAccount bankAccount) {
+
+    }
+
+    public Employee() {
+
     }
 
     public BankAccount getBankAccount() {
+
         return null;
     }
 
     public void setBankAccount(BankAccount bankAccount) {
 
     }
+
+    @Override
+    public void deposit(Double amountToIncreaseBy) {
+
+    }
+
+    @Override
+    public void withdrawal(Double amountToDecreaseBy) {
+
+    }
+
+    @Override
+    public Double getBalance() {
+        return null;
+    }
+
+    @Override
+    public void increaseHoursWorked(Double numberOfHours) {
+
+    }
+
+    @Override
+    public Double getHoursWorked() {
+        return null;
+    }
+
+    @Override
+    public Double getHourlyWage() {
+        return null;
+    }
+
+    @Override
+    public Double getMoneyEarned() {
+        return null;
+    }
 }
+

src/test/java/rocks/zipcode/quiz5/objectorientation/account/AccountPolymorphismTest.java

 import org.junit.Assert;
 import org.junit.Test;
 
+import java.util.List;
+
 /**
  * @author leon on 30/12/2018.
  */