part 7

src/main/java/ArrayListCombiner/ArrayListCombiner.java

@@ -8,7 +8,7 @@ import java.util.ArrayList;
  * The first method should be called extendCombiner and should use ? extends E
  * The second method should be called superCombiner and should use ? super E
  */
-public class ArrayListCombiner<E> {
+public class ArrayListCombiner {
 
     public static <E> void extendCombiner(ArrayList<E> first, ArrayList<? extends E> second) {
         first.addAll(second);

src/main/java/MapFunc/MapFunc.java

@@ -9,4 +9,13 @@ import java.util.function.Function;
  */
 public class MapFunc {
 
+    public static <T, R> ArrayList<R> map(ArrayList<T> input, Function<T, R> function) {
+        ArrayList<R> finalArray = new ArrayList<>();
+        for (T itemToChange : input) {
+            R result = function.apply(itemToChange);
+            finalArray.add(result);
+        }
+        return finalArray;
+    }
+
 }

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));
+    }
+
+}