raaudain · raaudain · Aug 23, 2019 · Aug 23, 2019 · Aug 23, 2019 · Aug 23, 2019
diff --git a/README.md b/README.md
@@ -30,14 +30,30 @@ Edit this document to include your answers after each question. Make sure to lea
 
 1. Describe the biggest difference between `.forEach` & `.map`.
 
+    .map is used when you want to convert data.
+
 2. What is the difference between a function and a method?
 
+    Methods have a "receiver" and functions don't.  For example: in ramon.indexOf(), ramon is the receiver.  For functions, like ramon(isGreat), there's now receiver.
+
 3. What is closure?
 
+    An inner function that has access to the outer functions' scope.
+
 4. Describe the four rules of the 'this' keyword.
 
+    1. Window/Global Object Binding: Whenever a function is contain in the globel scope, the value of "this" is equeal to the window object.
+
+    2. Implicit Binding: Whenever a function is called, the object to the left of the dot is what "this" is referring to.
+
+    3. New Binding: Whenever a constructor function is used, the "this" keyword is referring to the specific instance of the object that is created and returned by my constructor function.
+
+    4. Explicit Binding: Whenever "call" or "apply" is used, "this" is explicitly defined.
+
 5. Why do we need super() in an extended class?
 
+    super() calls the parent 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 +1,41 @@
 // 1. Copy and paste your prototype in here and refactor into class syntax.
 
+class NewCuboiMaker{
+    constructor(attr){
+        this.length = attr.length;
+        this.width = attr.width;
+        this.height = attr.height;
+    }
+    volume(){
+        return this.length * this.width * this.height;
+    }
+    surfaceArea(){
+        return 2 * (this.length*this.width + this.length*this.height + this.width*this.height);
+    }
+}
+
+class CubeMaker extends NewCuboiMaker{
+    constructor(attr) {
+        super(attr);
+    }
+    cubeVolume(){
+        return this.length*this.length*this.length; 
+    }
+    cubeSurfaceArea(){
+        return 6 * (this.length*this.length);
+    }
+}
+
+const newCuboid = new CubeMaker({
+    length: 4,
+    width: 5,
+    height: 5
+})
+
 // Test your volume and surfaceArea methods by uncommenting the logs below:
-// console.log(cuboid.volume()); // 100
-// console.log(cuboid.surfaceArea()); // 130
+console.log("Refactored: "+newCuboid.volume()); // 100
+console.log("Refactored: "+newCuboid.surfaceArea()); // 130
+console.log("Cube's volume: "+newCuboid.cubeVolume());
+console.log("Cube's surface area: "+newCuboid.cubeSurfaceArea());
 
 // 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.
diff --git a/challenges/functions.js b/challenges/functions.js
@@ -7,25 +7,39 @@
   * 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;
+}
+
+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!
+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: 
+// Explanation: Since nestedFunction is nested in myFunction, it has access to myFunction's scope.  The nestedFunction can look outside of its function to gain access to variables.
 
 
 const external = "I'm outside the function";

diff --git a/challenges/objects-arrays.js b/challenges/objects-arrays.js
@@ -14,21 +14,48 @@
 
 // Using your dinosaur objects, log answers to these questions:
 
+const tyrannosaurus = {
+  name: "tyrannosaurus",
+  diet: "carnivorous",
+  weight: "7000kg",
+  length: "12m",
+  period: "Late Cretaceous",
+  roar: function(){
+    return `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"
+}
+
 // How much did tyrannosaurus weigh?
-console.log();
+console.log(tyrannosaurus.name);
 
 // 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 ====
@@ -52,7 +79,12 @@ const graduates = [
 
 Once you have the new array created, sort the universities alphabetically and log the result. */
 const universities = [];
-console.log(universities);
+
+for(let i=0; i<graduates.length; i++){
+  universities.push(graduates[i].university);
+}
+
+console.log(universities.sort());
 
 /* 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 +93,16 @@ The resulting contact information strings should have a space between the first
 
 Log the result of your new array. */
 const contactInfo = [];
+
+for(let i=0; i<graduates.length; i++){
+  contactInfo.push(`${graduates[i].first_name} ${graduates[i].email}`);
+}
+
 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 = [];
+const unisWithUni = graduates.filter(uni => uni.university.includes("Uni"));
+
 console.log(unisWithUni);
 
 
@@ -91,6 +129,9 @@ The zoos want to display both the scientific name and the animal name in front o
 
 */
 const displayNames = [];
+
+zooAnimals.forEach(scienceName => displayNames.push(`Name: ${scienceName.animal_name}, Scientific: ${scienceName.scientific_name}`));
+
 console.log(displayNames);
 
 /* Request 2: .map()
@@ -100,22 +141,27 @@ The zoos need a list of all their animal's names (animal_name only) converted to
 */
 
 const lowCaseAnimalNames = [];
+
+zooAnimals.map(lowCase => lowCaseAnimalNames.push(`${lowCase.animal_name.toLowerCase()}`));
+
 console.log(lowCaseAnimalNames);
 
 /* Request 3: .filter() 
 
 The zoos are concerned about animals with a lower population count. Using filter, create a new array of objects called lowPopulationAnimals which contains only the animals with a population less than 5.
 
 */
-const lowPopulationAnimals = [];
+const lowPopulationAnimals = zooAnimals.filter(lowPop => lowPop.population < 5);
+
 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;
+const populationTotal = zooAnimals.reduce((acc,popCount) => acc+=popCount.population,0);
+
 console.log(populationTotal);
 
 

diff --git a/challenges/prototypes.js b/challenges/prototypes.js
@@ -6,28 +6,42 @@
   Create a constructor function named CuboidMaker that accepts properties for length, width, and height
 */
 
+function CuboiMaker(attr){
+  this.length = attr.length;
+  this.width = attr.width;
+  this.height = attr.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
 */
-
+CuboiMaker.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)
 */
-
+CuboiMaker.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.   
 */
+const cuboid = new CuboiMaker({
+  length: 4,
+  width: 5,
+  height: 5
+})
 
 // Test your volume and surfaceArea methods by uncommenting the logs below:
-// console.log(cuboid.volume()); // 100
-// console.log(cuboid.surfaceArea()); // 130
+console.log(cuboid.volume()); // 100
+console.log(cuboid.surfaceArea()); // 130