exercise 19 switched Object.create() over to Object.assign()

index.html

@@ -2146,29 +2146,15 @@ <h4>Exercise 19: Reducing with an initial value</h4>
 				// ]
 				return videos.
 					reduce(function(accumulatedMap, video) {
+					var obj = {};
 
-						// Object.create() makes a fast copy of the accumulatedMap by
-						// creating a new object and setting the accumulatedMap to be the
-						// new object's prototype.
-						// Initially the new object is empty and has no members of its own,
-						// except a pointer to the object on which it was based. If an
-						// attempt to find a member on the new object fails, the new object
-						// silently attempts to find the member on its prototype. This
-						// process continues recursively, with each object checking its
-						// prototype until the member is found or we reach the first object
-						// we created.
-						// If we set a member value on the new object, it is stored
-						// directly on that object, leaving the prototype unchanged.
-						// Object.create() is perfect for functional programming because it
-						// makes creating a new object with a different member value almost
-						// as cheap as changing the member on the original object!
-
-						var copyOfAccumulatedMap = Object.create(accumulatedMap);
-
-						// ----- INSERT CODE TO ADD THE VIDEO TITLE TO THE ----
-						// ----- NEW MAP USING THE VIDEO ID AS THE KEY	 ----
-
-						return copyOfAccumulatedMap;
+					// ----- INSERT CODE TO ADD THE VIDEO TITLE TO THE ----
+					// ----- NEW MAP USING THE VIDEO ID AS THE KEY	 ----
+
+					// Object.assign() takes all of the enumerable properties from
+					// the object listed in its second argument (obj) and assigns them
+					// to the object listed in its first argument (accumulatedMap).
+					return Object.assign(accumulatedMap, obj);
 					},
 					// Use an empty map as the initial value instead of the first item in
 					// the list.
@@ -2230,28 +2216,16 @@ <h4>Exercise 19: Reducing with an initial value</h4>
 				// ]
 				return videos.
 					reduce(function(accumulatedMap, video) {
+					var obj = {};
+
+					// ----- INSERT CODE TO ADD THE VIDEO TITLE TO THE ----
+					// ----- NEW MAP USING THE VIDEO ID AS THE KEY	 ----
+					obj[video.id] = video.title;
 
-						// Object.create() makes a fast copy of the accumulatedMap by
-						// creating a new object and setting the accumulatedMap to be the
-						// new object's prototype.
-						// Initially the new object is empty and has no members of its own,
-						// except a pointer to the object on which it was based. If an
-						// attempt to find a member on the new object fails, the new object
-						// silently attempts to find the member on its prototype. This
-						// process continues recursively, with each object checking its
-						// prototype until the member is found or we reach the first object
-						// we created.
-						// If we set a member value on the new object, it is stored
-						// directly on that object, leaving the prototype unchanged.
-						// Object.create() is perfect for functional programming because it
-						// makes creating a new object with a different member value almost
-						// as cheap as changing the member on the original object!
-
-						var copyOfAccumulatedMap = Object.create(accumulatedMap);
-
-						copyOfAccumulatedMap[video.id] = video.title;
-
-						return copyOfAccumulatedMap;
+					// Object.assign() takes all of the enumerable properties from
+					// the object listed in its second argument (obj) and assigns them
+					// to the object listed in its first argument (accumulatedMap).
+					return Object.assign(accumulatedMap, obj);
 					},
 					// Use an empty map as the initial value instead of the first item in
 					// the list.