abhisekp · June 12, 2016 20:23
diff --git a/# LearnRx Exercises.md b/# LearnRx Exercises.md
diff --git a/Exercise 01.js b/Exercise 01.js
 function(console) {
 	var names = ["Ben", "Jafar", "Matt", "Priya", "Brian"],
 		counter;

 	for(counter = 0; counter < names.length; counter++) {
 		console.log(names[counter]);
 	}
 }
 		
diff --git a/Exercise 02.js b/Exercise 02.js
 function(console) {
 	var names = ["Ben", "Jafar", "Matt", "Priya", "Brian"];

 	names.forEach(function(name) {
 		console.log(name);
 	});
 }
 		
diff --git a/Exercise 03.js b/Exercise 03.js
 function() {
 	var newReleases = [
 		{
 			"id": 70111470,
 			"title": "Die Hard",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/DieHard.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": [4.0],
 			"bookmark": []
 		},
 		{
 			"id": 654356453,
 			"title": "Bad Boys",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/BadBoys.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": [5.0],
 			"bookmark": [{ id:432534, time:65876586 }]
 		},
 		{
 			"id": 65432445,
 			"title": "The Chamber",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/TheChamber.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": [4.0],
 			"bookmark": []
 		},
 		{
 			"id": 675465,
 			"title": "Fracture",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/Fracture.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": [5.0],
 			"bookmark": [{ id:432534, time:65876586 }]
 		}
 	],
 	videoAndTitlePairs = [];

 	// ------------ INSERT CODE HERE! -----------------------------------
 	// Use forEach function to accumulate {id, title} pairs from each video.
 	// Put the results into the videoAndTitlePairs array using the Array's
 	// push() method. Example: videoAndTitlePairs.push(newItem);
 	// ------------ INSERT CODE HERE! -----------------------------------
  newReleases.forEach(release => videoAndTitlePairs.push({
                      id: release.id,
                      title: release.title
                      }));

 	return videoAndTitlePairs;
 }
 		
diff --git a/Exercise 04.js b/Exercise 04.js
 Array.prototype.map = function(projectionFunction) {
 	var results = [];
 	this.forEach(function(itemInArray) {

 		// ------------ INSERT CODE HERE! ----------------------------
 		// Apply the projectionFunction to each item in the array and add
 		// each result to the results array.
 		// Note: you can add items to an array with the push() method.
 		// ------------ INSERT CODE HERE! ----------------------------
 		results.push(projectionFunction(itemInArray));
 	});

 	return results;
 };

 // JSON.stringify([1,2,3].map(function(x) { return x + 1; })) === '[2,3,4]'
 		
diff --git a/Exercise 05.js b/Exercise 05.js
 function() {
 	var newReleases = [
 		{
 			"id": 70111470,
 			"title": "Die Hard",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/DieHard.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": [4.0],
 			"bookmark": []
 		},
 		{
 			"id": 654356453,
 			"title": "Bad Boys",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/BadBoys.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": [5.0],
 			"bookmark": [{ id:432534, time:65876586 }]
 		},
 		{
 			"id": 65432445,
 			"title": "The Chamber",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/TheChamber.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": [4.0],
 			"bookmark": []
 		},
 		{
 			"id": 675465,
 			"title": "Fracture",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/Fracture.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": [5.0],
 			"bookmark": [{ id:432534, time:65876586 }]
 		}
 	];

 	// ------------ INSERT CODE HERE! -----------------------------------
 	// Use map function to accumulate {id, title} pairs from each video.
 	return newReleases
    .map(rel => ({id: rel.id, title: rel.title}))
    
    // finish this expression!
 	// ------------ INSERT CODE HERE! -----------------------------------

 }
 		
diff --git a/Exercise 06.js b/Exercise 06.js
 function() {
 	var newReleases = [
 		{
 			"id": 70111470,
 			"title": "Die Hard",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/DieHard.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": 4.0,
 			"bookmark": []
 		},
 		{
 			"id": 654356453,
 			"title": "Bad Boys",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/BadBoys.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": 5.0,
 			"bookmark": [{ id:432534, time:65876586 }]
 		},
 		{
 			"id": 65432445,
 			"title": "The Chamber",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/TheChamber.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": 4.0,
 			"bookmark": []
 		},
 		{
 			"id": 675465,
 			"title": "Fracture",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/Fracture.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": 5.0,
 			"bookmark": [{ id:432534, time:65876586 }]
 		}
 	],
 	videos = [];

 	// ------------ INSERT CODE HERE! -----------------------------------
 	// Use forEach function to accumulate every video with a rating of 5.0
 	// ------------ INSERT CODE HERE! -----------------------------------

  newReleases.forEach(rel => rel.rating === 5 && videos.push(rel));
 	return videos;
 }
 		
diff --git a/Exercise 07.js b/Exercise 07.js
 Array.prototype.filter = function(predicateFunction) {
 	var results = [];
 	this.forEach(function(itemInArray) {
 		// ------------ INSERT CODE HERE! ----------------------------
 		// Apply the predicateFunction to each item in the array.
 		// If the result is truthy, add the item to the results array.
 		// Note: remember you can add items to the array using the array's
 		// push() method.
 		// ------------ INSERT CODE HERE! ----------------------------
    predicateFunction(itemInArray) && results.push(itemInArray);
 	});

 	return results;
 };

 // JSON.stringify([1,2,3].filter(function(x) { return x > 2})) === "[3]"
 		
diff --git a/Exercise 08.js b/Exercise 08.js
 function() {
 	var newReleases = [
 		{
 			"id": 70111470,
 			"title": "Die Hard",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/DieHard.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": 4.0,
 			"bookmark": []
 		},
 		{
 			"id": 654356453,
 			"title": "Bad Boys",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/BadBoys.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": 5.0,
 			"bookmark": [{ id:432534, time:65876586 }]
 		},
 		{
 			"id": 65432445,
 			"title": "The Chamber",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/TheChamber.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": 4.0,
 			"bookmark": []
 		},
 		{
 			"id": 675465,
 			"title": "Fracture",
 			"boxart": "http://cdn-0.nflximg.com/images/2891/Fracture.jpg",
 			"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 			"rating": 5.0,
 			"bookmark": [{ id:432534, time:65876586 }]
 		}
 	];

 	// ------------ INSERT CODE HERE! -----------------------------------
 	// Chain the filter and map functions to select the id of all videos
 	// with a rating of 5.0.

 	return newReleases 
    .filter(rel => rel.rating === 5)
    .map(rel => rel.id);
    // Complete this expression
 	// ------------ INSERT CODE HERE! -----------------------------------
 }
 		
diff --git a/Exercise 09.js b/Exercise 09.js
 function() {
 	var movieLists = [
 		{
 			name: "New Releases",
 			videos: [
 				{
 					"id": 70111470,
 					"title": "Die Hard",
 					"boxart": "http://cdn-0.nflximg.com/images/2891/DieHard.jpg",
 					"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 					"rating": 4.0,
 					"bookmark": []
 				},
 				{
 					"id": 654356453,
 					"title": "Bad Boys",
 					"boxart": "http://cdn-0.nflximg.com/images/2891/BadBoys.jpg",
 					"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 					"rating": 5.0,
 					"bookmark": [{ id:432534, time:65876586 }]
 				}
 			]
 		},
 		{
 			name: "Dramas",
 			videos: [
 				{
 					"id": 65432445,
 					"title": "The Chamber",
 					"boxart": "http://cdn-0.nflximg.com/images/2891/TheChamber.jpg",
 					"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 					"rating": 4.0,
 					"bookmark": []
 				},
 				{
 					"id": 675465,
 					"title": "Fracture",
 					"boxart": "http://cdn-0.nflximg.com/images/2891/Fracture.jpg",
 					"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 					"rating": 5.0,
 					"bookmark": [{ id:432534, time:65876586 }]
 				}
 			]
 		}
 	],
 	allVideoIdsInMovieLists = [];

 	// ------------   INSERT CODE HERE!  -----------------------------------
 	// Use two nested forEach loops to flatten the movieLists into a list of
 	// video ids.
 	// ------------   INSERT CODE HERE!  -----------------------------------
  movieLists.forEach(
    cat => cat.videos
    	.forEach(
  			video => allVideoIdsInMovieLists.push(video.id)
  		)
  );

 	return allVideoIdsInMovieLists;

 }
 		
diff --git a/Exercise 10.js b/Exercise 10.js
 Array.prototype.concatAll = function() {
 	var results = [];
 	this.forEach(function(subArray) {
 		// ------------ INSERT CODE HERE! ----------------------------
 		// Add all the items in each subArray to the results array.
 		// ------------ INSERT CODE HERE! ----------------------------
    subArray.forEach(item => results.push(item));
 	});

 	return results;
 };

 // JSON.stringify([ [1,2,3], [4,5,6], [7,8,9] ].concatAll()) === "[1,2,3,4,5,6,7,8,9]"
 // [1,2,3].concatAll(); // throws an error because this is a one-dimensional array
 		
diff --git a/Exercise 11.js b/Exercise 11.js
 function() {
 	var movieLists = [
 			{
 				name: "New Releases",
 				videos: [
 					{
 						"id": 70111470,
 						"title": "Die Hard",
 						"boxart": "http://cdn-0.nflximg.com/images/2891/DieHard.jpg",
 						"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 4.0,
 						"bookmark": []
 					},
 					{
 						"id": 654356453,
 						"title": "Bad Boys",
 						"boxart": "http://cdn-0.nflximg.com/images/2891/BadBoys.jpg",
 						"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 5.0,
 						"bookmark": [{ id:432534, time:65876586 }]
 					}
 				]
 			},
 			{
 				name: "Dramas",
 				videos: [
 					{
 						"id": 65432445,
 						"title": "The Chamber",
 						"boxart": "http://cdn-0.nflximg.com/images/2891/TheChamber.jpg",
 						"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 4.0,
 						"bookmark": []
 					},
 					{
 						"id": 675465,
 						"title": "Fracture",
 						"boxart": "http://cdn-0.nflximg.com/images/2891/Fracture.jpg",
 						"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 5.0,
 						"bookmark": [{ id:432534, time:65876586 }]
 					}
 				]
 			}
 		];

 	// ------------   INSERT CODE HERE!  -----------------------------------
 	// Use map and concatAll to flatten the movieLists in a list of video ids.
 	// ------------   INSERT CODE HERE!  -----------------------------------

 	return movieLists
    .map(
      cat => cat.videos
      	.map(video => video.id)        
    )
    .concatAll();
    // Complete this expression!

 }
 		
diff --git a/Exercise 12.js b/Exercise 12.js
 function() {
 	var movieLists = [
 			{
 				name: "Instant Queue",
 				videos : [
 					{
 						"id": 70111470,
 						"title": "Die Hard",
 						"boxarts": [
 							{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/DieHard150.jpg" },
 							{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/DieHard200.jpg" }
 						],
 						"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 4.0,
 						"bookmark": []
 					},
 					{
 						"id": 654356453,
 						"title": "Bad Boys",
 						"boxarts": [
 							{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/BadBoys200.jpg" },
 							{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/BadBoys150.jpg" }

 						],
 						"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 5.0,
 						"bookmark": [{ id:432534, time:65876586 }]
 					}
 				]
 			},
 			{
 				name: "New Releases",
 				videos: [
 					{
 						"id": 65432445,
 						"title": "The Chamber",
 						"boxarts": [
 							{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/TheChamber150.jpg" },
 							{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/TheChamber200.jpg" }
 						],
 						"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 4.0,
 						"bookmark": []
 					},
 					{
 						"id": 675465,
 						"title": "Fracture",
 						"boxarts": [
 							{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture200.jpg" },
 							{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture150.jpg" },
 							{ width: 300, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture300.jpg" }
 						],
 						"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 5.0,
 						"bookmark": [{ id:432534, time:65876586 }]
 					}
 				]
 			}
 		];


 	// Use one or more map, concatAll, and filter calls to create an array with the following items
 	// [
 	//	 {"id": 675465,"title": "Fracture","boxart":"http://cdn-0.nflximg.com/images/2891/Fracture150.jpg" },
 	//	 {"id": 65432445,"title": "The Chamber","boxart":"http://cdn-0.nflximg.com/images/2891/TheChamber150.jpg" },
 	//	 {"id": 654356453,"title": "Bad Boys","boxart":"http://cdn-0.nflximg.com/images/2891/BadBoys150.jpg" },
 	//	 {"id": 70111470,"title": "Die Hard","boxart":"http://cdn-0.nflximg.com/images/2891/DieHard150.jpg" }
 	// ];

 	return movieLists
    .map(
      cat => cat.videos
      	.map(
      		video => video.boxarts.filter(art => (art.width === 150 && art.height === 200))
      			.map(
              art => ({
               id: video.id,
               title: video.title,
               boxart: art.url
              })
            )
    		).concatAll()
    ).concatAll();
         
    // Complete this expression!

 }
 		
diff --git a/Exercise 13.js b/Exercise 13.js
 Array.prototype.concatMap = function(projectionFunctionThatReturnsArray) {
 	return this.
 		map(function(item) {
 			// ------------   INSERT CODE HERE!  ----------------------------
 			// Apply the projection function to each item. The projection
 			// function will return an new child array. This will create a
 			// two-dimensional array.
 			// ------------   INSERT CODE HERE!  ----------------------------
      return projectionFunctionThatReturnsArray(item);
 		}).
 		// apply the concatAll function to flatten the two-dimensional array
 		concatAll();
 };

 /*
 	var spanishFrenchEnglishWords = [ ["cero","rien","zero"], ["uno","un","one"], ["dos","deux","two"] ];
 	// collect all the words for each number, in every language, in a single, flat list
 	var allWords = [0,1,2].
 		concatMap(function(index) {
 			return spanishFrenchEnglishWords[index];
 		});

 	return JSON.stringify(allWords) === '["cero","rien","zero","uno","un","one","dos","deux","two"]';
 */
 		
diff --git a/Exercise 14.js b/Exercise 14.js
 function() {
 	var movieLists = [
 			{
 				name: "Instant Queue",
 				videos : [
 					{
 						"id": 70111470,
 						"title": "Die Hard",
 						"boxarts": [
 							{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/DieHard150.jpg" },
 							{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/DieHard200.jpg" }
 						],
 						"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 4.0,
 						"bookmark": []
 					},
 					{
 						"id": 654356453,
 						"title": "Bad Boys",
 						"boxarts": [
 							{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/BadBoys200.jpg" },
 							{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/BadBoys150.jpg" }

 						],
 						"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 5.0,
 						"bookmark": [{ id:432534, time:65876586 }]
 					}
 				]
 			},
 			{
 				name: "New Releases",
 				videos: [
 					{
 						"id": 65432445,
 						"title": "The Chamber",
 						"boxarts": [
 							{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/TheChamber150.jpg" },
 							{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/TheChamber200.jpg" }
 						],
 						"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 4.0,
 						"bookmark": []
 					},
 					{
 						"id": 675465,
 						"title": "Fracture",
 						"boxarts": [
 							{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture200.jpg" },
 							{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture150.jpg" },
 							{ width: 300, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture300.jpg" }
 						],
 						"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 5.0,
 						"bookmark": [{ id:432534, time:65876586 }]
 					}
 				]
 			}
 		];


 	// Use one or more concatMap, map, and filter calls to create an array with the following items
 	// [
 	//	 {"id": 675465,"title": "Fracture","boxart":"http://cdn-0.nflximg.com/images/2891/Fracture150.jpg" },
 	//	 {"id": 65432445,"title": "The Chamber","boxart":"http://cdn-0.nflximg.com/images/2891/TheChamber150.jpg" },
 	//	 {"id": 654356453,"title": "Bad Boys","boxart":"http://cdn-0.nflximg.com/images/2891/BadBoys150.jpg" },
 	//	 {"id": 70111470,"title": "Die Hard","boxart":"http://cdn-0.nflximg.com/images/2891/DieHard150.jpg" }
 	// ];

 	return movieLists
    .concatMap(cat => cat.videos
              .concatMap(video => video.boxarts
              	.filter(art => (art.width === 150 && art.height === 200))
      					.map(
                  art => ({
                    id: video.id,
                    title: video.title,
                    boxart: art.url
                  })
                )
              )
              )
    // Complete this expression!

 }
 		
diff --git a/Exercise 15.js b/Exercise 15.js
 function() {
 	var boxarts = [
 			{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture200.jpg" },
 			{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture150.jpg" },
 			{ width: 300, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture300.jpg" },
 			{ width: 425, height:150, url:"http://cdn-0.nflximg.com/images/2891/Fracture425.jpg" }
 		],
 		currentSize,
 		maxSize = -1,
 		largestBoxart;

 	boxarts.forEach(function(boxart) {
 		currentSize = boxart.width * boxart.height;
 		if (currentSize > maxSize) {
 			largestBoxart = boxart;
 			maxSize = currentSize;
 		}
 	});

 	return largestBoxart;
 }
 		
diff --git a/Exercise 16.js b/Exercise 16.js
 // [1,2,3].reduce(function(accumulatedValue, currentValue) { return accumulatedValue + currentValue; }); === [6];
 // [1,2,3].reduce(function(accumulatedValue, currentValue) { return accumulatedValue + currentValue; }, 10); === [16];

 Array.prototype.reduce = function(combiner, initialValue) {
 	var counter,
 		accumulatedValue;

 	// If the array is empty, do nothing
 	if (this.length === 0) {
 		return this;
 	}
 	else {
 		// If the user didn't pass an initial value, use the first item.
 		if (arguments.length === 1) {
 			counter = 1;
 			accumulatedValue = this[0];
 		}
 		else if (arguments.length >= 2) {
 			counter = 0;
 			accumulatedValue = initialValue;
 		}
 		else {
 			throw "Invalid arguments.";
 		}

 		// Loop through the array, feeding the current value and the result of
 		// the previous computation back into the combiner function until
 		// we've exhausted the entire array and are left with only one value.
 		while(counter < this.length) {
 			accumulatedValue = combiner(accumulatedValue, this[counter])
 			counter++;
 		}

 		return [accumulatedValue];
 	}
 };
 		
diff --git a/Exercise 17.js b/Exercise 17.js
 function() {
 	var ratings = [2,3,1,4,5];

 	// You should return an array containing only the largest rating. Remember that reduce always
 	// returns an array with one item.
 	return ratings.
    reduce((acc, curr) => acc > curr? acc : curr)   // Complete this expression
 }
 		
diff --git a/Exercise 18.js b/Exercise 18.js
 function() {
 	var boxarts = [
 			{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture200.jpg" },
 			{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture150.jpg" },
 			{ width: 300, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture300.jpg" },
 			{ width: 425, height:150, url:"http://cdn-0.nflximg.com/images/2891/Fracture425.jpg" }
 		];

 	// You should return an array containing only the URL of the largest box art. Remember that reduce always
 	// returns an array with one item.
 	return boxarts.
    reduce((acc, curr) => acc.width * acc.height > curr.width * curr.height ? acc : curr)
    .map(art => art.url); // Complete this expression
 }
 		
diff --git a/Exercise 19.js b/Exercise 19.js
 function() {
 	var videos = [
 		{
 			"id": 65432445,
 			"title": "The Chamber"
 		},
 		{
 			"id": 675465,
 			"title": "Fracture"
 		},
 		{
 			"id": 70111470,
 			"title": "Die Hard"
 		},
 		{
 			"id": 654356453,
 			"title": "Bad Boys"
 		}
 	];

 	// Expecting this output...
 	// [
 	//	 {
 	//		 "65432445": "The Chamber",
 	//		 "675465": "Fracture",
 	//		 "70111470": "Die Hard",
 	//		 "654356453": "Bad Boys"
 	//	 }
 	// ]
 	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.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.
 		{});
 }
 		
diff --git a/Exercise 20.js b/Exercise 20.js
 function() {
 	var movieLists = [
 		{
 			name: "New Releases",
 			videos: [
 				{
 					"id": 70111470,
 					"title": "Die Hard",
 					"boxarts": [
 						{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/DieHard150.jpg" },
 						{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/DieHard200.jpg" }
 					],
 					"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 					"rating": 4.0,
 					"bookmark": []
 				},
 				{
 					"id": 654356453,
 					"title": "Bad Boys",
 					"boxarts": [
 						{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/BadBoys200.jpg" },
 						{ width: 140, height:200, url:"http://cdn-0.nflximg.com/images/2891/BadBoys140.jpg" }

 					],
 					"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 					"rating": 5.0,
 					"bookmark": [{ id:432534, time:65876586 }]
 				}
 			]
 		},
 		{
 			name: "Thrillers",
 			videos: [
 				{
 					"id": 65432445,
 					"title": "The Chamber",
 					"boxarts": [
 						{ width: 130, height:200, url:"http://cdn-0.nflximg.com/images/2891/TheChamber130.jpg" },
 						{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/TheChamber200.jpg" }
 					],
 					"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 					"rating": 4.0,
 					"bookmark": []
 				},
 				{
 					"id": 675465,
 					"title": "Fracture",
 					"boxarts": [
 						{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture200.jpg" },
 						{ width: 120, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture120.jpg" },
 						{ width: 300, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture300.jpg" }
 					],
 					"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 					"rating": 5.0,
 					"bookmark": [{ id:432534, time:65876586 }]
 				}
 			]
 		}
 	];


 	// Use one or more concatMap, map, and reduce calls to create an array with the following items (order doesn't matter)
 	// [
 	//	 {"id": 675465,"title": "Fracture","boxart":"http://cdn-0.nflximg.com/images/2891/Fracture120.jpg" },
 	//	 {"id": 65432445,"title": "The Chamber","boxart":"http://cdn-0.nflximg.com/images/2891/TheChamber130.jpg" },
 	//	 {"id": 654356453,"title": "Bad Boys","boxart":"http://cdn-0.nflximg.com/images/2891/BadBoys140.jpg" },
 	//	 {"id": 70111470,"title": "Die Hard","boxart":"http://cdn-0.nflximg.com/images/2891/DieHard150.jpg" }
 	// ];

  var area = function(width, height) {
  	return width * height; 
  };
  
 	return movieLists.
 		concatMap(function(movieList) {
 			return movieList.videos.
        concatMap(function(video) {
          return video.boxarts.
            reduce(function(smallest, current) {
          		var smallestSize = area(smallest.width, smallest.height);
              var currentSize =  area(current.width, current.height);              
              return smallestSize < currentSize ? smallest : current;
            }).
            map(function(art) {
              return {
                id: video.id,
                title: video.title,
                boxart: art.url
              }
            })
        })
 		})

 }
 		
diff --git a/Exercise 21.js b/Exercise 21.js
 function() {
 	var videos = [
 			{
 				"id": 70111470,
 				"title": "Die Hard",
 				"boxart": "http://cdn-0.nflximg.com/images/2891/DieHard.jpg",
 				"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 				"rating": 4.0,
 			},
 			{
 				"id": 654356453,
 				"title": "Bad Boys",
 				"boxart": "http://cdn-0.nflximg.com/images/2891/BadBoys.jpg",
 				"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 				"rating": 5.0,
 			},
 			{
 				"id": 65432445,
 				"title": "The Chamber",
 				"boxart": "http://cdn-0.nflximg.com/images/2891/TheChamber.jpg",
 				"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 				"rating": 4.0,
 			},
 			{
 				"id": 675465,
 				"title": "Fracture",
 				"boxart": "http://cdn-0.nflximg.com/images/2891/Fracture.jpg",
 				"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 				"rating": 5.0,
 			}
 		],
 		bookmarks = [
 			{id: 470, time: 23432},
 			{id: 453, time: 234324},
 			{id: 445, time: 987834}
 		],
 	counter,
 	videoIdAndBookmarkIdPairs = [];

 	for(counter = 0; counter < Math.min(videos.length, bookmarks.length); counter++) {
 		// Insert code here to create a {videoId, bookmarkId} pair and add it to the videoIdAndBookmarkIdPairs array.
    videoIdAndBookmarkIdPairs.push({
      videoId: videos[counter].id,
      bookmarkId: bookmarks[counter].id
    })
 	}

  return videoIdAndBookmarkIdPairs;
 }
 		
diff --git a/Exercise 22.js b/Exercise 22.js
 // JSON.stringify(Array.zip([1,2,3],[4,5,6], function(left, right) { return left + right })) === '[5,7,9]'

 Array.zip = function(left, right, combinerFunction) {
 	var counter,
 		results = [];

 	for(counter = 0; counter < Math.min(left.length, right.length); counter++) {
 		// Add code here to apply the combinerFunction to the left and right-hand items in the respective arrays
    results.push(combinerFunction(left[counter], right[counter]));
 	}

 	return results;
 };
 		
diff --git a/Exercise 23.js b/Exercise 23.js
 function() {
 	var videos = [
 			{
 				"id": 70111470,
 				"title": "Die Hard",
 				"boxart": "http://cdn-0.nflximg.com/images/2891/DieHard.jpg",
 				"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 				"rating": 4.0,
 			},
 			{
 				"id": 654356453,
 				"title": "Bad Boys",
 				"boxart": "http://cdn-0.nflximg.com/images/2891/BadBoys.jpg",
 				"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 				"rating": 5.0,
 			},
 			{
 				"id": 65432445,
 				"title": "The Chamber",
 				"boxart": "http://cdn-0.nflximg.com/images/2891/TheChamber.jpg",
 				"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 				"rating": 4.0,
 			},
 			{
 				"id": 675465,
 				"title": "Fracture",
 				"boxart": "http://cdn-0.nflximg.com/images/2891/Fracture.jpg",
 				"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
 				"rating": 5.0,
 			}
 		],
 		bookmarks = [
 			{id: 470, time: 23432},
 			{id: 453, time: 234324},
 			{id: 445, time: 987834}
 		];

 	return Array.
    zip(videos, bookmarks, function (video, bookmark) {
      return {
        videoId: video.id,
        bookmarkId: bookmark.id
      };
    });
      //... finish this expression
 }
 		
diff --git a/Exercise 24.js b/Exercise 24.js
 function() {
 	var movieLists = [
 			{
 				name: "New Releases",
 				videos: [
 					{
 						"id": 70111470,
 						"title": "Die Hard",
 						"boxarts": [
 							{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/DieHard150.jpg" },
 							{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/DieHard200.jpg" }
 						],
 						"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 4.0,
 						"interestingMoments": [
 							{ type: "End", time:213432 },
 							{ type: "Start", time: 64534 },
 							{ type: "Middle", time: 323133}
 						]
 					},
 					{
 						"id": 654356453,
 						"title": "Bad Boys",
 						"boxarts": [
 							{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/BadBoys200.jpg" },
 							{ width: 140, height:200, url:"http://cdn-0.nflximg.com/images/2891/BadBoys140.jpg" }

 						],
 						"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 5.0,
 						"interestingMoments": [
 							{ type: "End", time:54654754 },
 							{ type: "Start", time: 43524243 },
 							{ type: "Middle", time: 6575665}
 						]
 					}
 				]
 			},
 			{
 				name: "Instant Queue",
 				videos: [
 					{
 						"id": 65432445,
 						"title": "The Chamber",
 						"boxarts": [
 							{ width: 130, height:200, url:"http://cdn-0.nflximg.com/images/2891/TheChamber130.jpg" },
 							{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/TheChamber200.jpg" }
 						],
 						"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 4.0,
 						"interestingMoments": [
 							{ type: "End", time:132423 },
 							{ type: "Start", time: 54637425 },
 							{ type: "Middle", time: 3452343}
 						]
 					},
 					{
 						"id": 675465,
 						"title": "Fracture",
 						"boxarts": [
 							{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture200.jpg" },
 							{ width: 120, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture120.jpg" },
 							{ width: 300, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture300.jpg" }
 						],
 						"url": "http://api.netflix.com/catalog/titles/movies/70111470",
 						"rating": 5.0,
 						"interestingMoments": [
 							{ type: "End", time:45632456 },
 							{ type: "Start", time: 234534 },
 							{ type: "Middle", time: 3453434}
 						]
 					}
 				]
 			}
 		];

 	//------------ COMPLETE THIS EXPRESSION --------------
  var area = function (width, height) {
  	return width * height; 
  }
  
 	return movieLists.
 		concatMap(function(movieList) {
      return movieList.videos.
        concatMap(function (video) {
          return Array.zip(video.boxarts.
              reduce(function (smallArt, currArt) {
              	var smallArtArea = area(smallArt.width, smallArt.height);
                var currArtArea = area(currArt.width, currArt.height);
                
                return smallArtArea < currArtArea ? smallArt : currArt;
              }), 
              video.interestingMoments.
              filter(function (moment) {
              	return moment.type === 'Middle';
              }),
              function (art, moment) {
                return {
                  id: video.id,
                  title: video.title,
                  time: moment.time,
                  url: art.url
                };
              });
        })
 		});

 }
 		
diff --git a/Exercise 25.js b/Exercise 25.js
 function() {
 	var lists = [
 			{
 				"id": 5434364,
 				"name": "New Releases"
 			},
 			{
 				"id": 65456475,
 				"name": "Thrillers"
 			}
 		],
 		videos = [
 			{
 				"listId": 5434364,
 				"id": 65432445,
 				"title": "The Chamber"
 			},
 			{
 				"listId": 5434364,
 				"id": 675465,
 				"title": "Fracture"
 			},
 			{
 				"listId": 65456475,
 				"id": 70111470,
 				"title": "Die Hard"
 			},
 			{
 				"listId": 65456475,
 				"id": 654356453,
 				"title": "Bad Boys"
 			}
 		];

 	return lists.
    map(function (list) {
      return {
        name: list.name,
        videos: videos.
        filter(function (video) {
          return video.listId === list.id;
        }).
        map(function (video) {
          return {
            id: video.id,
            title: video.title
          }
        })
      };
    });
    // complete this expression
 }
 		
diff --git a/Exercise 26.js b/Exercise 26.js
 function () {
  var lists = [{
      "id": 5434364,
      "name": "New Releases"
    }, {
      "id": 65456475,
      name: "Thrillers"
    }],
    videos = [{
      "listId": 5434364,
      "id": 65432445,
      "title": "The Chamber"
    }, {
      "listId": 5434364,
      "id": 675465,
      "title": "Fracture"
    }, {
      "listId": 65456475,
      "id": 70111470,
      "title": "Die Hard"
    }, {
      "listId": 65456475,
      "id": 654356453,
      "title": "Bad Boys"
    }],
    boxarts = [{
      videoId: 65432445,
      width: 130,
      height: 200,
      url: "http://cdn-0.nflximg.com/images/2891/TheChamber130.jpg"
    }, {
      videoId: 65432445,
      width: 200,
      height: 200,
      url: "http://cdn-0.nflximg.com/images/2891/TheChamber200.jpg"
    }, {
      videoId: 675465,
      width: 200,
      height: 200,
      url: "http://cdn-0.nflximg.com/images/2891/Fracture200.jpg"
    }, {
      videoId: 675465,
      width: 120,
      height: 200,
      url: "http://cdn-0.nflximg.com/images/2891/Fracture120.jpg"
    }, {
      videoId: 675465,
      width: 300,
      height: 200,
      url: "http://cdn-0.nflximg.com/images/2891/Fracture300.jpg"
    }, {
      videoId: 70111470,
      width: 150,
      height: 200,
      url: "http://cdn-0.nflximg.com/images/2891/DieHard150.jpg"
    }, {
      videoId: 70111470,
      width: 200,
      height: 200,
      url: "http://cdn-0.nflximg.com/images/2891/DieHard200.jpg"
    }, {
      videoId: 654356453,
      width: 200,
      height: 200,
      url: "http://cdn-0.nflximg.com/images/2891/BadBoys200.jpg"
    }, {
      videoId: 654356453,
      width: 140,
      height: 200,
      url: "http://cdn-0.nflximg.com/images/2891/BadBoys140.jpg"
    }],
    bookmarks = [{
      videoId: 65432445,
      time: 32432
    }, {
      videoId: 675465,
      time: 3534543
    }, {
      videoId: 70111470,
      time: 645243
    }, {
      videoId: 654356453,
      time: 984934
    }];

  var area = function (width, height) {
    return width * height;
  };

  return lists.
  map(function (list) {
    var _videos = videos.filter(function (video) {
        return video.listId === list.id;
      })
      .
    concatMap(function (video) {
      var _boxarts = boxarts.filter(function (boxart) {
          return boxart.videoId === video.id;
        })
        .
      reduce(function (smallBoxart, currBoxart) {
        var smallBoxartArea = area(smallBoxart.width, smallBoxart.height);
        var currBoxartArea = area(currBoxart.width, currBoxart.height);

        return smallBoxartArea < currBoxartArea ? smallBoxart : currBoxart;
      });

      var _bookmarks = bookmarks.filter(function (bookmark) {
        return bookmark.videoId === video.id;
      });

      return Array.zip(_boxarts, _bookmarks, function (boxart, bookmark) {
        return {
          id: video.id,
          title: video.title,
          time: bookmark.time,
          boxart: boxart.url
        };
      });
    });


    return {
      name: list.name,
      videos: _videos
    };
  });
  // complete this expression

 }
diff --git a/Exercise 27.js b/Exercise 27.js
 function(pricesNASDAQ, printRecord) {
 	var microsoftPrices,
 		now = new Date(),
 		tenDaysAgo = new Date( now.getFullYear(), now.getMonth(), now.getDate() - 10);

 	// use filter() to filter the trades for MSFT prices recorded any time after 10 days ago
 	microsoftPrices =
 		pricesNASDAQ.
    filter(function MSFTrecord(priceRecord) {
      return priceRecord.name === 'MSFT';
    }).
 			filter(function last10Days(priceRecord) {
        return now - priceRecord.timeStamp < tenDaysAgo;
      });// finish this expression

 	// Print the trades to the output console
 	microsoftPrices.
 		forEach(function(priceRecord) {
 			printRecord(priceRecord);
 		});
 }
 		
diff --git a/Exercise 28.js b/Exercise 28.js
 function(button) {
 	// the button click handler
 	var handler = function(ev) {
 		// Unsubscribe from the button event.
 		button.removeEventListener("click", handler);

 		alert("Button was clicked. Unsubscribing from event.");
 	};

 	// add the button click handler
 	button.addEventListener("click", handler);
 }
	function(console) {
	var names = ["Ben", "Jafar", "Matt", "Priya", "Brian"],
	counter;

	for(counter = 0; counter < names.length; counter++) {
	console.log(names[counter]);
	}
	}
	function(console) {
	var names = ["Ben", "Jafar", "Matt", "Priya", "Brian"];

	names.forEach(function(name) {
	console.log(name);
	});
	}
	function() {
	var newReleases = [
	{
	"id": 70111470,
	"title": "Die Hard",
	"boxart": "http://cdn-0.nflximg.com/images/2891/DieHard.jpg",
	"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
	"rating": [4.0],
	"bookmark": []
	},
	{
	"id": 654356453,
	"title": "Bad Boys",
	"boxart": "http://cdn-0.nflximg.com/images/2891/BadBoys.jpg",
	"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
	"rating": [5.0],
	"bookmark": [{ id:432534, time:65876586 }]
	},
	{
	"id": 65432445,
	"title": "The Chamber",
	"boxart": "http://cdn-0.nflximg.com/images/2891/TheChamber.jpg",
	"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
	"rating": [4.0],
	"bookmark": []
	},
	{
	"id": 675465,
	"title": "Fracture",
	"boxart": "http://cdn-0.nflximg.com/images/2891/Fracture.jpg",
	"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
	"rating": [5.0],
	"bookmark": [{ id:432534, time:65876586 }]
	}
	],
	videoAndTitlePairs = [];

	// ------------ INSERT CODE HERE! -----------------------------------
	// Use forEach function to accumulate {id, title} pairs from each video.
	// Put the results into the videoAndTitlePairs array using the Array's
	// push() method. Example: videoAndTitlePairs.push(newItem);
	// ------------ INSERT CODE HERE! -----------------------------------
	newReleases.forEach(release => videoAndTitlePairs.push({
	id: release.id,
	title: release.title
	}));

	return videoAndTitlePairs;
	}
	Array.prototype.map = function(projectionFunction) {
	var results = [];
	this.forEach(function(itemInArray) {

	// ------------ INSERT CODE HERE! ----------------------------
	// Apply the projectionFunction to each item in the array and add
	// each result to the results array.
	// Note: you can add items to an array with the push() method.
	// ------------ INSERT CODE HERE! ----------------------------
	results.push(projectionFunction(itemInArray));
	});

	return results;
	};

	// JSON.stringify([1,2,3].map(function(x) { return x + 1; })) === '[2,3,4]'
	Array.prototype.filter = function(predicateFunction) {
	var results = [];
	this.forEach(function(itemInArray) {
	// ------------ INSERT CODE HERE! ----------------------------
	// Apply the predicateFunction to each item in the array.
	// If the result is truthy, add the item to the results array.
	// Note: remember you can add items to the array using the array's
	// push() method.
	// ------------ INSERT CODE HERE! ----------------------------
	predicateFunction(itemInArray) && results.push(itemInArray);
	});

	return results;
	};

	// JSON.stringify([1,2,3].filter(function(x) { return x > 2})) === "[3]"
	function() {
	var movieLists = [
	{
	name: "New Releases",
	videos: [
	{
	"id": 70111470,
	"title": "Die Hard",
	"boxart": "http://cdn-0.nflximg.com/images/2891/DieHard.jpg",
	"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
	"rating": 4.0,
	"bookmark": []
	},
	{
	"id": 654356453,
	"title": "Bad Boys",
	"boxart": "http://cdn-0.nflximg.com/images/2891/BadBoys.jpg",
	"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
	"rating": 5.0,
	"bookmark": [{ id:432534, time:65876586 }]
	}
	]
	},
	{
	name: "Dramas",
	videos: [
	{
	"id": 65432445,
	"title": "The Chamber",
	"boxart": "http://cdn-0.nflximg.com/images/2891/TheChamber.jpg",
	"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
	"rating": 4.0,
	"bookmark": []
	},
	{
	"id": 675465,
	"title": "Fracture",
	"boxart": "http://cdn-0.nflximg.com/images/2891/Fracture.jpg",
	"uri": "http://api.netflix.com/catalog/titles/movies/70111470",
	"rating": 5.0,
	"bookmark": [{ id:432534, time:65876586 }]
	}
	]
	}
	],
	allVideoIdsInMovieLists = [];

	// ------------ INSERT CODE HERE! -----------------------------------
	// Use two nested forEach loops to flatten the movieLists into a list of
	// video ids.
	// ------------ INSERT CODE HERE! -----------------------------------
	movieLists.forEach(
	cat => cat.videos
	.forEach(
	video => allVideoIdsInMovieLists.push(video.id)
	)
	);

	return allVideoIdsInMovieLists;

	}
	Array.prototype.concatAll = function() {
	var results = [];
	this.forEach(function(subArray) {
	// ------------ INSERT CODE HERE! ----------------------------
	// Add all the items in each subArray to the results array.
	// ------------ INSERT CODE HERE! ----------------------------
	subArray.forEach(item => results.push(item));
	});

	return results;
	};

	// JSON.stringify([ [1,2,3], [4,5,6], [7,8,9] ].concatAll()) === "[1,2,3,4,5,6,7,8,9]"
	// [1,2,3].concatAll(); // throws an error because this is a one-dimensional array
	function() {
	var movieLists = [
	{
	name: "Instant Queue",
	videos : [
	{
	"id": 70111470,
	"title": "Die Hard",
	"boxarts": [
	{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/DieHard150.jpg" },
	{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/DieHard200.jpg" }
	],
	"url": "http://api.netflix.com/catalog/titles/movies/70111470",
	"rating": 4.0,
	"bookmark": []
	},
	{
	"id": 654356453,
	"title": "Bad Boys",
	"boxarts": [
	{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/BadBoys200.jpg" },
	{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/BadBoys150.jpg" }

	],
	"url": "http://api.netflix.com/catalog/titles/movies/70111470",
	"rating": 5.0,
	"bookmark": [{ id:432534, time:65876586 }]
	}
	]
	},
	{
	name: "New Releases",
	videos: [
	{
	"id": 65432445,
	"title": "The Chamber",
	"boxarts": [
	{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/TheChamber150.jpg" },
	{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/TheChamber200.jpg" }
	],
	"url": "http://api.netflix.com/catalog/titles/movies/70111470",
	"rating": 4.0,
	"bookmark": []
	},
	{
	"id": 675465,
	"title": "Fracture",
	"boxarts": [
	{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture200.jpg" },
	{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture150.jpg" },
	{ width: 300, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture300.jpg" }
	],
	"url": "http://api.netflix.com/catalog/titles/movies/70111470",
	"rating": 5.0,
	"bookmark": [{ id:432534, time:65876586 }]
	}
	]
	}
	];


	// Use one or more map, concatAll, and filter calls to create an array with the following items
	// [
	// {"id": 675465,"title": "Fracture","boxart":"http://cdn-0.nflximg.com/images/2891/Fracture150.jpg" },
	// {"id": 65432445,"title": "The Chamber","boxart":"http://cdn-0.nflximg.com/images/2891/TheChamber150.jpg" },
	// {"id": 654356453,"title": "Bad Boys","boxart":"http://cdn-0.nflximg.com/images/2891/BadBoys150.jpg" },
	// {"id": 70111470,"title": "Die Hard","boxart":"http://cdn-0.nflximg.com/images/2891/DieHard150.jpg" }
	// ];

	return movieLists
	.map(
	cat => cat.videos
	.map(
	video => video.boxarts.filter(art => (art.width === 150 && art.height === 200))
	.map(
	art => ({
	id: video.id,
	title: video.title,
	boxart: art.url
	})
	)
	).concatAll()
	).concatAll();

	// Complete this expression!

	}
	Array.prototype.concatMap = function(projectionFunctionThatReturnsArray) {
	return this.
	map(function(item) {
	// ------------ INSERT CODE HERE! ----------------------------
	// Apply the projection function to each item. The projection
	// function will return an new child array. This will create a
	// two-dimensional array.
	// ------------ INSERT CODE HERE! ----------------------------
	return projectionFunctionThatReturnsArray(item);
	}).
	// apply the concatAll function to flatten the two-dimensional array
	concatAll();
	};

	/*
	var spanishFrenchEnglishWords = [ ["cero","rien","zero"], ["uno","un","one"], ["dos","deux","two"] ];
	// collect all the words for each number, in every language, in a single, flat list
	var allWords = [0,1,2].
	concatMap(function(index) {
	return spanishFrenchEnglishWords[index];
	});

	return JSON.stringify(allWords) === '["cero","rien","zero","uno","un","one","dos","deux","two"]';
	*/
	function() {
	var boxarts = [
	{ width: 200, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture200.jpg" },
	{ width: 150, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture150.jpg" },
	{ width: 300, height:200, url:"http://cdn-0.nflximg.com/images/2891/Fracture300.jpg" },
	{ width: 425, height:150, url:"http://cdn-0.nflximg.com/images/2891/Fracture425.jpg" }
	],
	currentSize,
	maxSize = -1,
	largestBoxart;

	boxarts.forEach(function(boxart) {
	currentSize = boxart.width * boxart.height;
	if (currentSize > maxSize) {
	largestBoxart = boxart;
	maxSize = currentSize;
	}
	});

	return largestBoxart;
	}