finished advanced JS mini

app.js

@@ -1,28 +1,62 @@
 /* The four rules for 'this';
 * in your own words. explain the four rules for the "this" keyword below.
-* 1. 
-* 2. 
-* 3. 
-* 4. 
+* 1. Whenever a function has a global scope, this refers to the window object
+* 2. Whenever a function is called by a preceding dot, the object before the dot is this.
+* 3. When a constructor function is used, this refers to the specific instance of
+                the object created/returned by the constructor function
+* 4. With call and apply, this is explicitly defined
 * write out a code example of each explanation above
 */
 
 // First Rule
-
+// When in the global scope:
+//      console.log(this); -> points to window object
 // Second Rule
-
+      // const car = {
+      //   name: 'Corvette',
+      //   speed: 'extreme',
+      //   drive: function() {
+      //   console.log(`The car drove at ${this.speed} speeds.`);
+      //   console.log(this); -> refers to the car object
+      //   }
+      //}
 // Third Rule
-
+//          function food(name, foodGroup) {
+//            this.name = name;
+//            this.foodGroup = foodGroup;
+//            this.eat = function() {
+//            console.log(`You took a bite of your ${this.name}.`);
+//            console.log(this); -> this refers to the steak instance of the food class when steak.eat() is called
+//            }
+//}
+//            const steak = new food('steak', 'meat');
+//            steak.eat(); -> prints out "You took a bite....." and then steak on the next line
+//
 // Fourth Rule * you may want to use your third rule's example to accomplish this
-
-// explain closure 
+//                            Copied and pasted from rule #3:
+//          function food(name, foodGroup) {
+//            this.name = name;
+//            this.foodGroup = foodGroup;
+//            this.eat = function() {
+//            console.log(`You took a bite of your ${this.name}.`);
+//            console.log(this);
+//            }
+//          }
+//            const steak = new food('steak', 'meat');
+//            steak.eat();
+//            const celery = new food('celery', 'veggies');
+//            steak.eat.call(celery); -> same as calling celery.eat()
+//
+// explain closure
+// a closure is an inner function that accesses one or more variabels outside of the scope of the defined function
 
 function foo () {
-  console.log(this); // what does this point to?
+  console.log(this); // what does this point to? This points to the global object
 };
 
 const counterFunction = () => {
-  // this code is broken. figure out why, and tell us where the closure is when you fix it
+  let count = 0;
+  // this code is broken. figure out why, and tell us where the closure is when you fix it -> this line, count needed a starting value
   const changeCount = (value) => {
     count += value;
   };
@@ -53,29 +87,47 @@ console.log(counter.total());
   // assign these properties you pass in with options to the constructors 'this' object.
   // add a speak() method to your object that when called will log out the car's make model and year.
 
+function Car(options) {
+  this.make = options.make;
+  this.model = options.model;
+  this.year = options.year;
+}
+
+Car.prototype.speak = function() {
+  console.log(`You are driving a ${this.year} ${this.make} ${this.model}.`);
+}
+
 // when you're done un comment the next few lines and run the file here in node `node app.js`.
 
-// const herby = new Car({make: 'Volkswagen', model: 'Beetle', year: '1963'});
-// console.log(herby.speak());
-// const goldfinger = new Car({make: 'Aston Martin', model: 'DB5', year: '1964'});
-// console.log(goldfinger.speak());
+const herby = new Car({make: 'Volkswagen', model: 'Beetle', year: '1963'});
+console.log(herby.speak());
+const goldfinger = new Car({make: 'Aston Martin', model: 'DB5', year: '1964'});
+console.log(goldfinger.speak());
+
 
+// once you get done with this, redo it all using the class keyword and a constructor function.
 
-// once you get done with this, redo it all using the class keyword and a constructor function. 
+class Car2 {
+  constructor(options) {
+    this.make = options.make;
+    this.model = options.model;
+    this.year = options.year;
+  }
+  speak() {
+    console.log(`You are driving a ${this.year} ${this.make} ${this.model}.`);
+  }
+}
 
 // extra credit
 
 // we didn't touch on Recursion in the lecture yet, but you're going to build a recursive function now
 
-
-let n = 10;
-while(n >= 1) {
-  console.log(n);
-  n--;
+const countDown = (n) => {
+  if (n >= 1) {
+    console.log(n);
+    n--;
+    countDown(n);
+  }
 }
 // write a function called countDown that does the exact same thing as above, but calls itself until it can't anymore.
   // hint-> your base case will look like the logic in the while loop.
-
-
-
-