Neytoro · Neytoro · Nov 15, 2019
diff --git a/README.md b/README.md
@@ -30,14 +30,28 @@ Edit this document to include your answers after each question. Make sure to lea
 
 1. Describe the biggest difference between `.forEach` & `.map`.
 
+The core difference is that .forEach doesn't return anything, whereas .map returns a new array.
+Therefore, .forEach mutates the array being iterated, but .map does not.
+
 2. What is the difference between a function and a method?
 
+Functions are their own thing, where as methods are simply functions nested into objects; such as prototypes or classes.
+
 3. What is closure?
 
+Closure refers to the closing, or nesting of functions. For example, a function created within another is 'closed' within its parent function; thus gaining access to the private scope of its parent. That said, closure is important when understanding the scope.
+
 4. Describe the four rules of the 'this' keyword.
 
+1. In the global scope, it refers to the window. 
+2. When inside a function, it refers to the object before the dot.
+3. When used in a constructor, it acts to assign (or bind) a value to the specific instance.
+4. Overriding how constructor values are set by explicitly binding. Done using .call and/or .apply. 
+
 5. Why do we need super() in an extended class?
 
+Super passes the arguements in the extended class' constructor to its base class.
+
 ## Project Set up
 
 Follow these steps to set up and work on your project:

diff --git a/challenges/classes.js b/challenges/classes.js
@@ -1,7 +1,36 @@
 // 1. Copy and paste your prototype in here and refactor into class syntax.
 
+class CuboidMaker2 {
+    constructor(length, width, height) {
+        this.length = length;
+        this.width = width;
+        this.height = height;
+    }
+    volume() { return this.length * this.width * this.height; }
+    surfaceArea() { return 2 * (this.length * this.width + this.length * this.height + this.width * this.height); }
+}
+
+const cuboid2 = new CuboidMaker2(4, 5, 5);
+
 // Test your volume and surfaceArea methods by uncommenting the logs below:
-// console.log(cuboid.volume()); // 100
-// console.log(cuboid.surfaceArea()); // 130
+console.log(cuboid2.volume()); // 100
+console.log(cuboid2.surfaceArea()); // 130
+
+// Stretch Task: Extend the base class CuboidMaker with a sub class called CubeMaker.  Find out the formulas for volume and surface area for cubes and create those methods using the dimension properties from CuboidMaker.  Test your work by logging out your volume and surface area.
+class CubeMaker extends CuboidMaker2 {
+
+    constructor(length, width, height) {
+        super(length, width, height);
+    }
+
+    volume2() { return this.length * this.width * this.height; }
+    surfaceArea2() { return 2 * (this.length * this.width + this.length * this.height + this.width * this.height); }
+
+}
+
+const cuboid3 = new CubeMaker(4, 5, 5);
+
+console.log(cuboid3.volume2()); 
+console.log(cuboid3.surfaceArea2());
 
-// Stretch Task: Extend the base class CuboidMaker with a sub class called CubeMaker.  Find out the formulas for volume and surface area for cubes and create those methods using the dimension properties from CuboidMaker.  Test your work by logging out your volume and surface area.
+// I assume this is what was being asked? I dunno. Am big dumb.
diff --git a/challenges/functions.js b/challenges/functions.js
@@ -7,36 +7,48 @@
   * The consume function should return the invocation of cb, passing a and b into cb as arguments
 */
 
+function consume(a, b, cb) {
+  return cb(a, b);
+}
+
 
 /* Step 2: Create several functions to callback with consume();
   * Create a function named add that returns the sum of two numbers
   * Create a function named multiply that returns the product of two numbers 
   * Create a function named greeting that accepts a first and last name and returns "Hello first-name last-name, nice to meet you!"
 */
 
+function add(a, b) { return a + b; }
 
-/* Step 3: Check your work by un-commenting the following calls to consume(): */
-// console.log(consume(2, 2, add)); // 4
-// console.log(consume(10, 16, multiply)); // 160
-// console.log(consume("Mary", "Poppins", greeting)); // Hello Mary Poppins, nice to meet you!
+function multiply(a, b) { return a * b; }
 
+function greeting(a, b) { 
+  return 'Hello ' + a + ' ' + b + ', nice to meet you!';
+}
+
+/* Step 3: Check your work by un-commenting the following calls to consume(): */
+console.log(consume(2, 2, add)); // 4
+console.log(consume(10, 16, multiply)); // 160
+console.log(consume("Mary", "Poppins", greeting)); // Hello Mary Poppins, nice to meet you!
 
 // ==== Closures ==== 
 
 // Explain in your own words why nestedfunction can access the variable internal.
 
 // Explanation: 
-
+/*
+ Because the variable internal has a higher scope. Since it is inside the parent function, it can be accessed.
+*/
 
 const external = "I'm outside the function";
 
-function myFunction() {
+function myFunction() { // Parent function
   console.log(external);
   const internal = "Hello! I'm inside myFunction!";
 
-  function nestedFunction() {
+  function nestedFunction() { // Child function
     console.log(internal);
-  };
+  }; // Child scope end
   nestedFunction();
-}
+} // Parent scope end
 myFunction();
diff --git a/challenges/objects-arrays.js b/challenges/objects-arrays.js
@@ -12,23 +12,48 @@
 
 // velociraptor, carnivorous, 15kg, 1.8m, Late Cretaceous
 
+const tyrannosaurus = {
+  name: 'Tyrannosaurus',
+  diet: 'Carnivorous',
+  weight: '7000kg',
+  length: '12m',
+  period: 'Late Cretaceous',
+  roar: () => 'RAWERSRARARWERSARARARRRR!'
+};
+
+const stegosaurus = {
+  name: 'Stegosaurus',
+  diet: 'Herbivorous',
+  weight: '2000kg',
+  length: '9m',
+  period: 'Late Jurassic'
+};
+
+const velociraptor = {
+  name: 'Velociraptor',
+  diet: 'Carnivorous',
+  weight: '15kg',
+  length: '1.8m',
+  period: 'Late Cretaceous'
+};
+
 // Using your dinosaur objects, log answers to these questions:
 
 // How much did tyrannosaurus weigh?
-console.log();
+console.log(tyrannosaurus.weight);
 
 // What was the diet of a velociraptor?
-console.log();
+console.log(velociraptor.diet);
 
 // How long was a stegosaurus?
-console.log();
+console.log(stegosaurus.length);
 
 // What time period did tyrannosaurus live in?
-console.log();
+console.log(tyrannosaurus.period);
 
 
 // Create a new roar method for the tyrannosaurus.  When called, return "RAWERSRARARWERSARARARRRR!" Log the result.
-console.log();
+console.log(tyrannosaurus.roar());
 
 
 // ==== Arrays ====
@@ -52,6 +77,18 @@ const graduates = [
 
 Once you have the new array created, sort the universities alphabetically and log the result. */
 const universities = [];
+
+function sort() {
+
+  for (var i = 0; i < graduates.length; i++)
+    universities.push(graduates[i].university);
+
+  universities.sort();
+
+}
+
+sort();
+
 console.log(universities);
 
 /* Request 2: Create a new array called contactInfo that contains both first name and email of each student. This will be an array of strings.
@@ -61,10 +98,33 @@ The resulting contact information strings should have a space between the first
 
 Log the result of your new array. */
 const contactInfo = [];
+
+function grabContacts() {
+
+  graduates.forEach((element) => contactInfo.push(element.first_name + ' ' + element.email));
+
+}
+
+grabContacts();
+
 console.log(contactInfo);
 
 /* Request 3: Find out how many universities have the string "Uni" included in their name. Create a new array called unisWithUni that contains them all. This will be an array of objects. Log the result. */
 const unisWithUni = [];
+
+function grabUni() {
+
+  graduates.forEach((element) => {
+
+    if (element.university.includes('Uni'))
+      unisWithUni.push(element.university);
+
+  });
+
+}
+
+grabUni();
+
 console.log(unisWithUni);
 
 
@@ -91,6 +151,15 @@ The zoos want to display both the scientific name and the animal name in front o
 
 */
 const displayNames = [];
+
+function grabDisplayNames() {
+
+  zooAnimals.forEach((element) => displayNames.push('Name: ' + element.animal_name + ', Scientific: ' + element.scientific_name + '.'));
+
+}
+
+grabDisplayNames();
+
 console.log(displayNames);
 
 /* Request 2: .map()
@@ -100,6 +169,15 @@ The zoos need a list of all their animal's names (animal_name only) converted to
 */
 
 const lowCaseAnimalNames = [];
+
+function lowcaseAnimals() {
+
+  zooAnimals.map((element) => lowCaseAnimalNames.push(element.animal_name.toLowerCase()));
+
+}
+
+lowcaseAnimals();
+
 console.log(lowCaseAnimalNames);
 
 /* Request 3: .filter() 
@@ -108,20 +186,37 @@ The zoos are concerned about animals with a lower population count. Using filter
 
 */
 const lowPopulationAnimals = [];
+
+function filterPopulation() {
+
+  zooAnimals.filter((element) => element.population < 5).forEach((element) => lowPopulationAnimals.push(element));
+
+}
+
+filterPopulation();
+
 console.log(lowPopulationAnimals);
 
 /* Request 4: .reduce() 
 
 The zoos need to know their total animal population across the United States. Find the total population from all the zoos using the .reduce() method. Remember the reduce method takes two arguments: a callback (which itself takes two args), and an initial value for the count.
 
 */
-const populationTotal = 0;
-console.log(populationTotal);
+const populationTotal = totalPopulation();
+
+function totalPopulation() {
 
+  return zooAnimals.reduce((total, current) => total + current.population, 0);
+
+}
+
+console.log(populationTotal);
 
 /*
 
 Stretch: If you haven't already, convert your array method callbacks into arrow functions.
 
 */
 
+// Already done ;)
+
diff --git a/challenges/prototypes.js b/challenges/prototypes.js
@@ -5,29 +5,38 @@
 /* == Step 1: Base Constructor ==
   Create a constructor function named CuboidMaker that accepts properties for length, width, and height
 */
-
+function CuboidMaker(length, width, height) {
+  this.length = length;
+  this.width = width;
+  this.height = height;
+}
 
 /* == Step 2: Volume Method ==
   Create a method using CuboidMaker's prototype that returns the volume of a given cuboid's length, width, and height
 
   Formula for cuboid volume: length * width * height
 */
 
+CuboidMaker.prototype.volume = function() {
+  return this.length * this.width * this.height;
+};
 
 /* == Step 3: Surface Area Method ==
   Create another method using CuboidMaker's prototype that returns the surface area of a given cuboid's length, width, and height. 
 
   Formula for cuboid surface area of a cube: 2 * (length * width + length * height + width * height)
 */
-
+CuboidMaker.prototype.surfaceArea = function() { 
+  return 2 * (this.length * this.width + this.length * this.height + this.width * this.height);
+};
 
 /* == Step 4: Create a new object that uses CuboidMaker ==
   Create a cuboid object that uses the new keyword to use our CuboidMaker constructor
   Add properties and values of length: 4, width: 5, and height: 5 to cuboid.   
 */
 
-// Test your volume and surfaceArea methods by uncommenting the logs below:
-// console.log(cuboid.volume()); // 100
-// console.log(cuboid.surfaceArea()); // 130
-
+const cuboid = new CuboidMaker(4, 5, 5);
 
+// Test your volume and surfaceArea methods by uncommenting the logs below:
+console.log(cuboid.volume()); // 100
+console.log(cuboid.surfaceArea()); // 130