Merge e972bbaba53dd5f3af6ba5f2df604de783d9cf4c into 844bbe32418e760e4607b01fa37541c39badf9aa

src/main/java/ArrayListCombiner/ArrayListCombiner.java

@@ -1,5 +1,6 @@
 package ArrayListCombiner;
 
+import java.lang.reflect.Array;
 import java.util.ArrayList;
 
 /**
@@ -9,4 +10,20 @@ import java.util.ArrayList;
  * The second method should be called superCombiner and should use ? super E
  */
 public class ArrayListCombiner {
+
+    public static <E> void extendCombiner(ArrayList<E> first, ArrayList<? extends E> second){
+        first.addAll(second);
+    }
+
+    public static <E> void superCombiner(ArrayList<? super E> first, ArrayList<E> second){
+        first.addAll(second);
+    }
 }
+
+
+//to describe static in my head....
+//you don't need the juice to have the sauce
+//so for example, a class is the sauce...makes a meal what it is
+//an object is the juice, great flavor but not what you want with everymeal
+//if you check out the test, and you notice its not instantiated you don't need the juice
+//because the test already has the sauce

src/main/java/MapFunc/MapFunc.java

@@ -9,4 +9,16 @@ import java.util.function.Function;
  */
 public class MapFunc {
 
+    //okay katrice, so public method is because this test does not create a instance of MapFunc
+    //The <T, R> when its static you have to define the generic so you can pass it into a static
+    //We are returning an Arraylist of the results and they take in an ArrayList of type T
+    public static <T,R> ArrayList<R> map(ArrayList<T> lists, Function<T,R> function){
+        ArrayList<R> result = new ArrayList<>();
+        for(T item: lists){
+            R entry = function.apply(item);
+            result.add(entry);
+
+        }
+        return result;
+    }
 }

src/main/java/Pair/Arrays.java

@@ -11,6 +11,28 @@ import java.util.Collections;
  * And a minmax method that returns a pair containing the largest and smallest items from the array list
  */
 public class Arrays {
-    public static <___> Pair<E> firstLast(ArrayList<___> a) {
+    public static <E extends Comparable> Pair<E> firstLast(ArrayList<E> a) {
+        return new Pair(a.get(0), a.get(a.size()-1));
+    }
+
+
+    public static <E extends Comparable> E min(ArrayList<E> al) {
+
+        Collections.sort(al);
+        return al.get(0);
+    }
+
+
+    public static <E extends Comparable> E max(ArrayList<E> al) {
+
+        Collections.sort(al);
+        return al.get(al.size()-1);
+    }
+
+
+    public static <E extends Comparable> Pair<E> minMax(ArrayList<E> al) {
+
+        return new Pair<E>(min(al), max(al));
+
     }
 }

src/main/java/Pair/Pair.java

@@ -7,6 +7,33 @@ package Pair;
  * min -> returns the minimum of the pair
  * max -> returns the maximum of the pair
  */
-public class Pair {
+public class Pair<E extends Comparable> {
+    private E first;
+    private E second;
+
+    public Pair(E first, E second){
+        this.first = first;
+        this.second = second;
+    }
+
+    public E getFirst(){
+        return first;
+    }
+
+    public E getSecond(){
+        return second;
+    }
+
+    public E min(){
+        if(first.compareTo(second)>0);
+            return first;
+
+    }
+
+    public E max(){
+        if(first.compareTo(second)>0);
+            return second;
+
+    }
 
 }

src/main/java/StackArray/GenericStack.java

@@ -11,5 +11,31 @@ public class GenericStack<E> {
     private E[] elements;
 
     public GenericStack() {
+        this.elements = (E[]) new Object[0];
+    }
+
+    public E push(E value){
+        //needs to remove an element from E[] and resize
+        //now I just need to push the value onto the end of the array
+        E[] newArray = Arrays.copyOf(this.elements, this.elements.length + 1);
+        newArray[newArray.length-1] = value;
+        this.elements = newArray;
+        return value;
+
+    }
+
+    public E pop(){
+        //according to the api, pop should return a value
+        //didn't need to assign the value
+        E value = this.elements[elements.length-1];
+        E[] newArray = Arrays.copyOf(elements, elements.length - 1);
+        //newArray[newArray.length-1] = value;
+        this.elements = newArray;
+        return value;
+    }
+
+    public boolean isEmpty(){
+        return (elements.length==0);
+
     }
 }

src/main/java/StackArray/ObjectStack.java

@@ -11,6 +11,25 @@ public class ObjectStack<E> {
     private Object[] elements;
 
     public ObjectStack() {
+        this.elements = new Object[0];
+    }
+    //the way stacks work, its just like generics accept you are using Objects
+    public Object push(Object value){
+        Object[] newArray = Arrays.copyOf(this.elements, this.elements.length + 1);
+        newArray[newArray.length-1] = value;
+        this.elements = newArray;
+        return value;
+    }
+
+    public Object pop(){
+        Object value = this.elements[elements.length-1];
+        Object[] newArray = Arrays.copyOf(elements, elements.length - 1);
+        //newArray[newArray.length-1] = value;
+        this.elements = newArray;
+        return value;
+    }
 
+    public boolean isEmpty(){
+        return(elements.length==0);
     }
 }

src/main/java/StackArrayList/Stack.java

@@ -7,10 +7,28 @@ import java.util.ArrayList;
  * If you pop on an empty stack, throw an IndexOutOfBoundsException.
  */
 public class Stack<E> {
+
     private ArrayList elements;
 
 
     public Stack(){
+        this.elements = new ArrayList<E>();
+    }
+
+    public void push(E value){
+        //pushes adds an element
+        this.elements.add(value);
+    }
 
+    public E pop(){
+        //removes an element
+        return (E) elements.remove(this.elements.size()-1);
     }
+
+    public boolean isEmpty(){
+        //Checks to see is the elements array is empty, if its equal to 0 its empty.
+        return (elements.size()==0);
+    }
+
+
 }

src/main/java/Swap/Swap.java

@@ -11,3 +11,9 @@ public class Swap {
         return values;
     }
 }
+
+//Explanation
+//Stating Generic T is equal to the indexes i of values
+//those indexes are also equal to the indexes j of values
+//and index j of values equals temp
+//now return values

src/main/java/Table/Table.java

@@ -10,8 +10,46 @@ import java.util.ArrayList;
  * Void return on `remove`.
  */
 public class Table<K, V> {
-    private ArrayList entries;
+    private ArrayList<Entry> entries;
 
     public Table() {
+        this.entries = new ArrayList<>();
     }
+
+    public Object get(K key){
+        for(Entry e : entries){
+            if(e.getKey().equals(key)){
+                return e.getValue();
+            }
+        }
+        return null;
+    }
+
+    public void put(K key, V value){
+        //need to enter value and key into entry
+        int counter = 0;
+        for(Entry e : entries){
+            if(e.getKey().equals(key)){
+                entries.set(counter, new Entry<>(key, value));
+                return;
+            }
+        }
+        entries.add(new Entry<>(key, value));
+    }
+
+    public void remove(K key){
+        //needs to take a key, and if that key exists in the arraylist, remove the item
+        for(Entry e : entries){
+            if(e.getKey().equals(key)){
+                entries.remove(key);
+                return;
+            }
+        }
+
+
+    }
+
+
 }
+
+

src/main/java/TableNested/TableNested.java

@@ -7,5 +7,62 @@ import java.util.ArrayList;
  * Think about how nested classes should work with generics.
  */
 public class TableNested<K, V> {
+    private ArrayList<Table.Entry> entries;
 
+    public TableNested() {
+        this.entries = new ArrayList<>();
+    }
+
+    public Object get(K key) {
+        for (Table.Entry e : entries) {
+            if (e.getKey().equals(key)) {
+                return e.getValue();
+            }
+        }
+        return null;
+    }
+
+    public void put(K key, V value) {
+        //need to enter value and key into entry
+        int counter = 0;
+        for (Table.Entry e : entries) {
+            if (e.getKey().equals(key)) {
+                entries.set(counter, new Table.Entry<>(key, value));
+                return;
+            }
+        }
+        entries.add(new Table.Entry<>(key, value));
+    }
+
+    public void remove(K key) {
+        //needs to take a key, and if that key exists in the arraylist, remove the item
+        for (Table.Entry e : entries) {
+            if (e.getKey().equals(key)) {
+                entries.remove(e);
+                return;
+            }
+        }
+
+
+    }
+
+
+    public class Entry<K, V> {
+        private K key;
+        private V value;
+
+        public Entry(K key, V value) {
+            this.key = key;
+            this.value = value;
+        }
+
+        public K getKey() {
+            return key;
+        }
+
+        public V getValue() {
+            return value;
+        }
+
+    }
 }

src/test/java/ArrayListCombiner/ArrayListCombinerTest.java

@@ -9,40 +9,40 @@ import org.junit.Assert;
 import java.util.ArrayList;
 
 public class ArrayListCombinerTest {
-//    Employee foo = new Employee("FOO", 100);
-//    Manager bar = new Manager("BAR", 100);
-//    @Test
-//    public void testExtendCombiner() throws Exception {
-//        // Given an array list with employees
-//        ArrayList<Employee> first = new ArrayList<>();
-//        first.add(foo);
-//        // An an array list with managers
-//        ArrayList<Manager> second = new ArrayList<>();
-//        second.add(bar);
-//        // When  I combine them
-//        ArrayListCombiner.extendCombiner(first, second);
-//        // Then I should get an arrayList with both
-//        ArrayList<Employee> expected = new ArrayList<>();
-//        expected.add(foo);
-//        expected.add(bar);
-//        Assert.assertEquals(expected, first);
-//    }
-//
-//    @Test
-//    public void testSuperCombiner() throws Exception {
-//        // Given an array list with employees
-//        ArrayList<Employee> first = new ArrayList<>();
-//        first.add(foo);
-//        // An an array list with managers
-//        ArrayList<Manager> second = new ArrayList<>();
-//        second.add(bar);
-//        // When  I combine them
-//        ArrayListCombiner.superCombiner(first, second);
-//        // Then I should get an arrayList with both
-//        ArrayList<Employee> expected = new ArrayList<>();
-//        expected.add(foo);
-//        expected.add(bar);
-//        Assert.assertEquals(expected, first);
-//    }
+    Employee foo = new Employee("FOO", 100);
+    Manager bar = new Manager("BAR", 100);
+    @Test
+    public void testExtendCombiner() throws Exception {
+        // Given an array list with employees
+        ArrayList<Employee> first = new ArrayList<>();
+        first.add(foo);
+        // An an array list with managers
+        ArrayList<Manager> second = new ArrayList<>();
+        second.add(bar);
+        // When  I combine them
+        ArrayListCombiner.extendCombiner(first, second);
+        // Then I should get an arrayList with both
+        ArrayList<Employee> expected = new ArrayList<>();
+        expected.add(foo);
+        expected.add(bar);
+        Assert.assertEquals(expected, first);
+    }
+
+    @Test
+    public void testSuperCombiner() throws Exception {
+        // Given an array list with employees
+        ArrayList<Employee> first = new ArrayList<>();
+        first.add(foo);
+        // An an array list with managers
+        ArrayList<Manager> second = new ArrayList<>();
+        second.add(bar);
+        // When  I combine them
+        ArrayListCombiner.superCombiner(first, second);
+        // Then I should get an arrayList with both
+        ArrayList<Employee> expected = new ArrayList<>();
+        expected.add(foo);
+        expected.add(bar);
+        Assert.assertEquals(expected, first);
+    }
 
 }

src/test/java/MapFunc/MapFuncTest.java

@@ -1,36 +1,36 @@
-//package MapFunc;
-//
-//import MapFunc.MapFunc;
-//import org.junit.Test;
-//
-//import java.util.ArrayList;
-//import org.junit.Assert;
-//
-//public class MapFuncTest {
-//    @Test
-//    public void testSingleTypeMap() throws Exception {
-//        // Given an integer array list
-//        ArrayList<Integer> intList = new ArrayList<>();
-//        intList.add(1);
-//        intList.add(2);
-//        // When it's mapped with a function to double the value
-//        ArrayList<Integer> mappedList = MapFunc.map(intList, num -> num*2);
-//        // Then all the values are doubled
-//        Assert.assertEquals(new Integer(2), mappedList.get(0));
-//        Assert.assertEquals(new Integer(4), mappedList.get(1));
-//    }
-//
-//    @Test
-//    public void testMultipleTypeMap() throws Exception {
-//        // Given an integer array list
-//        ArrayList<Integer> intList = new ArrayList<>();
-//        intList.add(1);
-//        intList.add(2);
-//        // When it's mapped with to string
-//        ArrayList<String> mappedList = MapFunc.map(intList, num -> num.toString());
-//        // Then all the values are doubled
-//        Assert.assertEquals("1", mappedList.get(0));
-//        Assert.assertEquals("2", mappedList.get(1));
-//    }
-//
-//}
+package MapFunc;
+
+import MapFunc.MapFunc;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import org.junit.Assert;
+
+public class MapFuncTest {
+    @Test
+    public void testSingleTypeMap() throws Exception {
+        // Given an integer array list
+        ArrayList<Integer> intList = new ArrayList<>();
+        intList.add(1);
+        intList.add(2);
+        // When it's mapped with a function to double the value
+        ArrayList<Integer> mappedList = MapFunc.map(intList, num -> num*2);
+        // Then all the values are doubled
+        Assert.assertEquals(new Integer(2), mappedList.get(0));
+        Assert.assertEquals(new Integer(4), mappedList.get(1));
+    }
+
+    @Test
+    public void testMultipleTypeMap() throws Exception {
+        // Given an integer array list
+        ArrayList<Integer> intList = new ArrayList<>();
+        intList.add(1);
+        intList.add(2);
+        // When it's mapped with to string
+        ArrayList<String> mappedList = MapFunc.map(intList, num -> num.toString());
+        // Then all the values are doubled
+        Assert.assertEquals("1", mappedList.get(0));
+        Assert.assertEquals("2", mappedList.get(1));
+    }
+
+}

src/test/java/Pair/ArraysTest.java

@@ -1,74 +1,74 @@
-//package Pair;
-//
-//import org.junit.Assert;
-//import org.junit.Test;
-//
-//import java.util.ArrayList;
-//
-//public class ArraysTest {
-//    @Test
-//    public void firstLast() throws Exception {
-//        // Given an ArrayList of Integers
-//        ArrayList<Integer> al = new ArrayList<>();
-//        al.add(1);
-//        al.add(5);
-//        al.add(3);
-//        al.add(4);
-//        al.add(2);
-//        al.add(0);
-//        al.add(1000);
-//        // When firstLast is called
-//        Pair<Integer> result = Arrays.firstLast(al);
-//        // Then it should return the first and last items
-//        Assert.assertEquals(new Integer(1), result.getFirst());
-//        Assert.assertEquals(new Integer(1000), result.getSecond());
-//    }
-//
-//    @Test
-//    public void testMin() throws Exception {
-//        // Given an ArrayList of Integers
-//        ArrayList<Integer> al = new ArrayList<>();
-//        al.add(1);
-//        al.add(5);
-//        al.add(3);
-//        al.add(4);
-//        al.add(2);
-//        al.add(0);
-//        al.add(1000);
-//        // When min is called assert that it gets the smallest item
-//        Assert.assertEquals(new Integer(0), Arrays.min(al));
-//    }
-//
-//    @Test
-//    public void testMax() throws Exception {
-//        // Given an ArrayList of Integers
-//        ArrayList<Integer> al = new ArrayList<>();
-//        al.add(1);
-//        al.add(5);
-//        al.add(3);
-//        al.add(4);
-//        al.add(2);
-//        al.add(0);
-//        al.add(1000);
-//        // When min is called assert that it gets the largest item
-//        Assert.assertEquals(new Integer(1000), Arrays.max(al));
-//    }
-//
-//    @Test
-//    public void testMinMax() throws Exception {
-//        // Given an ArrayList of Integers
-//        ArrayList<Integer> al = new ArrayList<>();
-//        al.add(1);
-//        al.add(5);
-//        al.add(3);
-//        al.add(4);
-//        al.add(2);
-//        al.add(0);
-//        al.add(1000);
-//        // When minMax is called
-//        Pair<Integer> result = Arrays.minMax(al);
-//        // Then it should return the first and last items
-//        Assert.assertEquals(new Integer(0), result.min());
-//        Assert.assertEquals(new Integer(1000), result.max());
-//    }
-//}
+package Pair;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.ArrayList;
+
+public class ArraysTest {
+    @Test
+    public void firstLast() throws Exception {
+        // Given an ArrayList of Integers
+        ArrayList<Integer> al = new ArrayList<>();
+        al.add(1);
+        al.add(5);
+        al.add(3);
+        al.add(4);
+        al.add(2);
+        al.add(0);
+        al.add(1000);
+        // When firstLast is called
+        Pair<Integer> result = Arrays.firstLast(al);
+        // Then it should return the first and last items
+        Assert.assertEquals(new Integer(1), result.getFirst());
+        Assert.assertEquals(new Integer(1000), result.getSecond());
+    }
+
+    @Test
+    public void testMin() throws Exception {
+        // Given an ArrayList of Integers
+        ArrayList<Integer> al = new ArrayList<>();
+        al.add(1);
+        al.add(5);
+        al.add(3);
+        al.add(4);
+        al.add(2);
+        al.add(0);
+        al.add(1000);
+        // When min is called assert that it gets the smallest item
+        Assert.assertEquals(new Integer(0), Arrays.min(al));
+    }
+
+    @Test
+    public void testMax() throws Exception {
+        // Given an ArrayList of Integers
+        ArrayList<Integer> al = new ArrayList<>();
+        al.add(1);
+        al.add(5);
+        al.add(3);
+        al.add(4);
+        al.add(2);
+        al.add(0);
+        al.add(1000);
+        // When min is called assert that it gets the largest item
+        Assert.assertEquals(new Integer(1000), Arrays.max(al));
+    }
+
+    @Test
+    public void testMinMax() throws Exception {
+        // Given an ArrayList of Integers
+        ArrayList<Integer> al = new ArrayList<>();
+        al.add(1);
+        al.add(5);
+        al.add(3);
+        al.add(4);
+        al.add(2);
+        al.add(0);
+        al.add(1000);
+        // When minMax is called
+        Pair<Integer> result = Arrays.minMax(al);
+        // Then it should return the first and last items
+        Assert.assertEquals(new Integer(0), result.min());
+        Assert.assertEquals(new Integer(1000), result.max());
+    }
+}

src/test/java/Pair/PairTest.java

@@ -1,32 +1,32 @@
-//package Pair;
-//
-//import org.junit.Test;
-//import org.junit.Assert;
-//
-//public class PairTest {
-//
-//    @Test
-//    public void testGetters() throws Exception {
-//        // Given a pair with "Foo" and "Bar"
-//        Pair<String> p = new Pair<String>("Foo", "Bar");
-//        // When getFirst and getSecond are called, they should be returned.
-//        Assert.assertEquals("Foo", p.getFirst());
-//        Assert.assertEquals("Bar",  p.getSecond());
-//    }
-//
-//    @Test
-//    public void testMin() throws Exception {
-//        // Given a pair with two values
-//        Pair<Double> p = new Pair<Double>(1.23, 2.34);
-//        // When p.min() is called, the smallest should be returned.
-//        Assert.assertEquals(new Double(1.23), p.min());
-//    }
-//
-//    @Test
-//    public void testMax() throws Exception {
-//        // Given a pair with two values
-//        Pair<Double> p = new Pair<Double>(1.23, 2.34);
-//        // When p.max() is called, the largest should be returned.
-//        Assert.assertEquals(new Double(2.34), p.max());
-//    }
-//}
+package Pair;
+
+import org.junit.Test;
+import org.junit.Assert;
+
+public class PairTest {
+
+    @Test
+    public void testGetters() throws Exception {
+        // Given a pair with "Foo" and "Bar"
+        Pair<String> p = new Pair<String>("Foo", "Bar");
+        // When getFirst and getSecond are called, they should be returned.
+        Assert.assertEquals("Foo", p.getFirst());
+        Assert.assertEquals("Bar",  p.getSecond());
+    }
+
+    @Test
+    public void testMin() throws Exception {
+        // Given a pair with two values
+        Pair<Double> p = new Pair<Double>(1.23, 2.34);
+        // When p.min() is called, the smallest should be returned.
+        Assert.assertEquals(new Double(1.23), p.min());
+    }
+
+    @Test
+    public void testMax() throws Exception {
+        // Given a pair with two values
+        Pair<Double> p = new Pair<Double>(1.23, 2.34);
+        // When p.max() is called, the largest should be returned.
+        Assert.assertEquals(new Double(2.34), p.max());
+    }
+}

src/test/java/StackArray/GenericStackTest.java

@@ -1,41 +1,41 @@
-//package StackArray;
-//
-//import org.junit.Assert;
-//import org.junit.Test;
-//
-//public class GenericStackTest {
-//    @Test
-//    public void testPushingGrowsTheStack() throws Exception {
-//        // Given an empty stack
-//        GenericStack<String> stack = new GenericStack<>();
-//
-//        // Assert that it is empty.
-//        Assert.assertEquals(true, stack.isEmpty());
-//        // When we push something onto the stack
-//        stack.push("foobar");
-//        // Then it shouldn't be empty
-//        Assert.assertEquals(false, stack.isEmpty());
-//    }
-//
-//    @Test
-//    public void testPushingAndPoppingOrder() throws Exception {
-//        // Given an empty stack
-//        GenericStack<String> stack = new GenericStack<>();
-//        // When we push two elements on it
-//        stack.push("foo");
-//        stack.push("bar");
-//        // Then we should see them returned in the correct order
-//        Assert.assertEquals("bar", stack.pop());
-//        Assert.assertEquals("foo", stack.pop());
-//    }
-//
-//    @Test(expected = IndexOutOfBoundsException.class)
-//    public void testPopFirst() throws Exception {
-//        // Given an empty stack
-//        GenericStack<String> stack = new GenericStack<>();
-//        // When it's popped
-//        stack.pop();
-//        // Then we should get an exception
-//    }
-//
-//}
+package StackArray;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class GenericStackTest {
+    @Test
+    public void testPushingGrowsTheStack() throws Exception {
+        // Given an empty stack
+        GenericStack<String> stack = new GenericStack<>();
+
+        // Assert that it is empty.
+        Assert.assertEquals(true, stack.isEmpty());
+        // When we push something onto the stack
+        stack.push("foobar");
+        // Then it shouldn't be empty
+        Assert.assertEquals(false, stack.isEmpty());
+    }
+
+    @Test
+    public void testPushingAndPoppingOrder() throws Exception {
+        // Given an empty stack
+        GenericStack<String> stack = new GenericStack<>();
+        // When we push two elements on it
+        stack.push("foo");
+        stack.push("bar");
+        // Then we should see them returned in the correct order
+        Assert.assertEquals("bar", stack.pop());
+        Assert.assertEquals("foo", stack.pop());
+    }
+
+    @Test(expected = IndexOutOfBoundsException.class)
+    public void testPopFirst() throws Exception {
+        // Given an empty stack
+        GenericStack<String> stack = new GenericStack<>();
+        // When it's popped
+        stack.pop();
+        // Then we should get an exception
+    }
+
+}

src/test/java/StackArray/ObjectStackTest.java

@@ -1,39 +1,39 @@
-//package StackArray;
-//
-//import org.junit.Assert;
-//import org.junit.Test;
-//
-//public class ObjectStackTest {
-//    @Test
-//    public void testPushingGrowsTheStack() throws Exception {
-//        // Given an empty stack
-//        ObjectStack<String> stack = new ObjectStack<>();
-//        // Assert that it is empty.
-//        Assert.assertEquals(true, stack.isEmpty());
-//        // When we push something onto the stack
-//        stack.push("foobar");
-//        // Then it shouldn't be empty
-//        Assert.assertEquals(false, stack.isEmpty());
-//    }
-//
-//    @Test
-//    public void testPushingAndPoppingOrder() throws Exception {
-//        // Given an empty stack
-//        ObjectStack<String> stack = new ObjectStack<>();
-//        // When we push two elements on it
-//        stack.push("foo");
-//        stack.push("bar");
-//        // Then we should see them returned in the correct order
-//        Assert.assertEquals("bar", stack.pop());
-//        Assert.assertEquals("foo", stack.pop());
-//    }
-//
-//    @Test(expected = IndexOutOfBoundsException.class)
-//    public void testPopFirst() throws Exception {
-//        // Given an empty stack
-//        ObjectStack<String> stack = new ObjectStack<>();
-//        // When it's popped
-//        stack.pop();
-//        // Then we should get an exception
-//    }
-//}
+package StackArray;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class ObjectStackTest {
+    @Test
+    public void testPushingGrowsTheStack() throws Exception {
+        // Given an empty stack
+        ObjectStack<String> stack = new ObjectStack<>();
+        // Assert that it is empty.
+        Assert.assertEquals(true, stack.isEmpty());
+        // When we push something onto the stack
+        stack.push("foobar");
+        // Then it shouldn't be empty
+        Assert.assertEquals(false, stack.isEmpty());
+    }
+
+    @Test
+    public void testPushingAndPoppingOrder() throws Exception {
+        // Given an empty stack
+        ObjectStack<String> stack = new ObjectStack<>();
+        // When we push two elements on it
+        stack.push("foo");
+        stack.push("bar");
+        // Then we should see them returned in the correct order
+        Assert.assertEquals("bar", stack.pop());
+        Assert.assertEquals("foo", stack.pop());
+    }
+
+    @Test(expected = IndexOutOfBoundsException.class)
+    public void testPopFirst() throws Exception {
+        // Given an empty stack
+        ObjectStack<String> stack = new ObjectStack<>();
+        // When it's popped
+        stack.pop();
+        // Then we should get an exception
+    }
+}

src/test/java/StackArrayList/StackTest.java

@@ -1,45 +1,45 @@
-//package StackArrayList;
-//
-//import org.junit.Test;
-//
-//import org.junit.Assert;
-//
-//public class StackTest {
-//    @Test
-//    public void testEmptyStackStopsBeingEmptyWhenAnItemIsAdded() throws Exception {
-//        // Given an empty stack
-//        Stack<String> stack = new Stack<>();
-//        // Assert that it starts empty
-//        Assert.assertEquals(true, stack.isEmpty());
-//        // When an element gets pushed
-//        stack.push("foobar");
-//        // Then the stack should not be empty.
-//        Assert.assertEquals(false, stack.isEmpty());
-//    }
-//
-//    @Test
-//    public void testTwoItemsPushedComeOutInCorrectOrder() throws Exception {
-//        // Given an empty stack
-//        Stack<String> stack = new Stack<>();
-//
-//        //When two items are pushed
-//        stack.push("foo");
-//        stack.push("bar");
-//
-//        // Then they should come off in reverse order.
-//        Assert.assertEquals("bar", stack.pop());
-//        Assert.assertEquals("foo", stack.pop());
-//
-//        // And then the stack should be empty
-//        Assert.assertEquals(true, stack.isEmpty());
-//    }
-//
-//    @Test(expected = IndexOutOfBoundsException.class)
-//    public void testPopFirst() throws Exception {
-//        // Given an empty stack
-//        Stack<String> stack = new Stack<>();
-//        // Then it is popped
-//        stack.pop();
-//        // We should get an exception
-//    }
-//}
+package StackArrayList;
+
+import org.junit.Test;
+
+import org.junit.Assert;
+
+public class StackTest {
+    @Test
+    public void testEmptyStackStopsBeingEmptyWhenAnItemIsAdded() throws Exception {
+        // Given an empty stack
+        Stack<String> stack = new Stack<>();
+        // Assert that it starts empty
+        Assert.assertEquals(true, stack.isEmpty());
+        // When an element gets pushed
+        stack.push("foobar");
+        // Then the stack should not be empty.
+        Assert.assertEquals(false, stack.isEmpty());
+    }
+
+    @Test
+    public void testTwoItemsPushedComeOutInCorrectOrder() throws Exception {
+        // Given an empty stack
+        Stack<String> stack = new Stack<>();
+
+        //When two items are pushed
+        stack.push("foo");
+        stack.push("bar");
+
+        // Then they should come off in reverse order.
+        Assert.assertEquals("bar", stack.pop());
+        Assert.assertEquals("foo", stack.pop());
+
+        // And then the stack should be empty
+        Assert.assertEquals(true, stack.isEmpty());
+    }
+
+    @Test(expected = IndexOutOfBoundsException.class)
+    public void testPopFirst() throws Exception {
+        // Given an empty stack
+        Stack<String> stack = new Stack<>();
+        // Then it is popped
+        stack.pop();
+        // We should get an exception
+    }
+}

src/test/java/Swap/SwapTest.java

@@ -1,16 +1,24 @@
 package Swap;
-//
-//import org.junit.Assert;
-//import org.junit.Test;
-//
-///**
-// * Get the tests passing.
-// */
-//public class SwapTest {
-//    @Test
-//    public void testSwap() throws Exception {
-//        Double[] result = Swap.swap(0,1, 1.5, 2,3);
-//        Double[] expected = {2.0, 1.5, 3.0};
-//        Assert.assertArrayEquals(expected, result);
-//    }
-//}
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Get the tests passing.
+ */
+public class SwapTest {
+    @Test
+    public void testSwap() throws Exception {
+        Double[] result = Swap.swap(0,1, 1.5, 2.0, 3.0);
+        Double[] expected = {2.0, 1.5, 3.0};
+        Assert.assertArrayEquals(expected, result);
+    }
+}
+
+//Explanation
+//Stating Generic T is equal to the indexes i of values
+//those indexes are also equal to the indexes j of values
+//and index j of values equals temp
+//now return values
+
+//so 1.5 is value i & 2.3 is value j

src/test/java/Table/TableTest.java

@@ -1,50 +1,50 @@
-//package Table;
-//
-//import org.junit.Assert;
-//import org.junit.Test;
-//
-//public class TableTest {
-//    @Test
-//    public void testGetWithoutAnItemReturnsNull() throws Exception {
-//        // Given an empty table
-//        Table<String, Integer> table = new Table<String, Integer>();
-//        // When we try and get an item then it returns null
-//        Assert.assertEquals(table.get("foo"), null);
-//    }
-//
-//    @Test
-//    public void testPutAnItemReturnsAndDoesNotDelete() throws Exception {
-//        //Given an empty table
-//        Table<String, Integer> table = new Table<String, Integer>();
-//        // When we put an item in it
-//        table.put("foo", 1);
-//        // Then we should be able to get it's value
-//        Assert.assertEquals(table.get("foo"), new Integer(1));
-//        // And then we should be able to get it again as it wasn't removed
-//        Assert.assertEquals(table.get("foo"), new Integer(1));
-//    }
-//
-//    @Test
-//    public void testOverwritingAnItem() throws Exception {
-//        //Given an empty table
-//        Table<String, Integer> table = new Table<String, Integer>();
-//        // When we put an item in it
-//        table.put("foo", 1);
-//        // And we put a new value with the same key
-//        table.put("foo", 2);
-//        // Then we should get back the new value
-//        Assert.assertEquals(table.get("foo"), new Integer(2));
-//    }
-//
-//    @Test
-//    public void testRemoveAnItem() throws Exception {
-//        //Given an empty table
-//        Table<String, Integer> table = new Table<String, Integer>();
-//        // When we put an item in it
-//        table.put("foo", 1);
-//        // And we remove that item
-//        table.remove("foo");
-//        // Then we should get back null for that balue
-//        Assert.assertEquals(table.get("foo"), null);
-//    }
-//}
+package Table;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TableTest {
+    @Test
+    public void testGetWithoutAnItemReturnsNull() throws Exception {
+        // Given an empty table
+        Table<String, Integer> table = new Table<String, Integer>();
+        // When we try and get an item then it returns null
+        Assert.assertEquals(table.get("foo"), null);
+    }
+
+    @Test
+    public void testPutAnItemReturnsAndDoesNotDelete() throws Exception {
+        //Given an empty table
+        Table<String, Integer> table = new Table<String, Integer>();
+        // When we put an item in it
+        table.put("foo", 1);
+        // Then we should be able to get it's value
+        Assert.assertEquals(table.get("foo"), new Integer(1));
+        // And then we should be able to get it again as it wasn't removed
+        Assert.assertEquals(table.get("foo"), new Integer(1));
+    }
+
+    @Test
+    public void testOverwritingAnItem() throws Exception {
+        //Given an empty table
+        Table<String, Integer> table = new Table<String, Integer>();
+        // When we put an item in it
+        table.put("foo", 1);
+        // And we put a new value with the same key
+        table.put("foo", 2);
+        // Then we should get back the new value
+        Assert.assertEquals(table.get("foo"), new Integer(2));
+    }
+
+    @Test
+    public void testRemoveAnItem() throws Exception {
+        //Given an empty table
+        Table<String, Integer> table = new Table<String, Integer>();
+        // When we put an item in it
+        table.put("foo", 1);
+        // And we remove that item
+        table.remove("foo");
+        // Then we should get back null for that balue
+        Assert.assertEquals(table.get("foo"), null);
+    }
+}

src/test/java/TableNested/TableNestedTest.java

@@ -1,50 +1,50 @@
-//package TableNested;
-//
-//import org.junit.Assert;
-//import org.junit.Test;
-//
-//public class TableNestedTest {
-//    @Test
-//    public void testGetWithoutAnItemReturnsNull() throws Exception {
-//        // Given an empty table
-//        TableNested<String, Integer> table = new TableNested<String, Integer>();
-//        // When we try and get an item then it returns null
-//        Assert.assertEquals(table.get("foo"), null);
-//    }
-//
-//    @Test
-//    public void testPutAnItemReturnsAndDoesNotDelete() throws Exception {
-//        //Given an empty table
-//        TableNested<String, Integer> table = new TableNested<String, Integer>();
-//        // When we put an item in it
-//        table.put("foo", 1);
-//        // Then we should be able to get it's value
-//        Assert.assertEquals(table.get("foo"), new Integer(1));
-//        // And then we should be able to get it again as it wasn't removed
-//        Assert.assertEquals(table.get("foo"), new Integer(1));
-//    }
-//
-//    @Test
-//    public void testOverwritingAnItem() throws Exception {
-//        //Given an empty table
-//        TableNested<String, Integer> table = new TableNested<String, Integer>();
-//        // When we put an item in it
-//        table.put("foo", 1);
-//        // And we put a new value with the same key
-//        table.put("foo", 2);
-//        // Then we should get back the new value
-//        Assert.assertEquals(table.get("foo"), new Integer(2));
-//    }
-//
-//    @Test
-//    public void testRemoveAnItem() throws Exception {
-//        //Given an empty table
-//        TableNested<String, Integer> table = new TableNested<String, Integer>();
-//        // When we put an item in it
-//        table.put("foo", 1);
-//        // And we remove that item
-//        table.remove("foo");
-//        // Then we should get back null for that balue
-//        Assert.assertEquals(table.get("foo"), null);
-//    }
-//}
+package TableNested;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TableNestedTest {
+    @Test
+    public void testGetWithoutAnItemReturnsNull() throws Exception {
+        // Given an empty table
+        TableNested<String, Integer> table = new TableNested<String, Integer>();
+        // When we try and get an item then it returns null
+        Assert.assertEquals(table.get("foo"), null);
+    }
+
+    @Test
+    public void testPutAnItemReturnsAndDoesNotDelete() throws Exception {
+        //Given an empty table
+        TableNested<String, Integer> table = new TableNested<String, Integer>();
+        // When we put an item in it
+        table.put("foo", 1);
+        // Then we should be able to get it's value
+        Assert.assertEquals(table.get("foo"), new Integer(1));
+        // And then we should be able to get it again as it wasn't removed
+        Assert.assertEquals(table.get("foo"), new Integer(1));
+    }
+
+    @Test
+    public void testOverwritingAnItem() throws Exception {
+        //Given an empty table
+        TableNested<String, Integer> table = new TableNested<String, Integer>();
+        // When we put an item in it
+        table.put("foo", 1);
+        // And we put a new value with the same key
+        table.put("foo", 2);
+        // Then we should get back the new value
+        Assert.assertEquals(table.get("foo"), new Integer(2));
+    }
+
+    @Test
+    public void testRemoveAnItem() throws Exception {
+        //Given an empty table
+        TableNested<String, Integer> table = new TableNested<String, Integer>();
+        // When we put an item in it
+        table.put("foo", 1);
+        // And we remove that item
+        table.remove("foo");
+        // Then we should get back null for that balue
+        Assert.assertEquals(table.get("foo"), null);
+    }
+}