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69 changes: 52 additions & 17 deletions app.js
Original file line number Diff line number Diff line change
@@ -1,28 +1,50 @@
/* The four rules for 'this';
* in your own words. explain the four rules for the "this" keyword below.
* 1.
* 2.
* 3.
* 4.
* 1. When a function if in the Global scope this equals the window object
* 2. when a function is called by a preceeding dot the object before the dot is this
* 3. in a constructor function this refers to the specific object returned to the object
* 4. with call or apply this is defined in the method
* write out a code example of each explanation above
*/

function thisFunction() {
this;
};
// this === window
// First Rule

const second = {
name: 'Dylan',
anything: function() {
return `${this}`;
}
}
// this === second
// Second Rule

class Person {
constructor(options) {
this.name = options.name
this.greet = () => {
console.log(`${this.name}`);
};
}
}
const dylan = new Person({name: 'Dylan'});
const other = new Person({name: 'anon'});
//this=== person whos options are passed into the constructor for the specific instance
// Third Rule

dylan.greet.call(other);
//this===other
// Fourth Rule * you may want to use your third rule's example to accomplish this

// explain closure

// closure deals with accessing variables. You can only access variables in own scope or an outer scope.
function foo () {
console.log(this); // what does this point to?
console.log(this); // what does this point to? the window
};

const counterFunction = () => {
// this code is broken. figure out why, and tell us where the closure is when you fix it
let count = 0; //count must be intialized
const changeCount = (value) => {
count += value;
};
Expand All @@ -46,7 +68,16 @@ counter.increment();
counter.increment();
console.log(counter.total());


class Car {
constructor(options) {
this.make = options.make;
this.model = options.model;
this.year = options.year;
}
speak() {
console.log(`${this.make} ${this.model} ${this.year}`)
}
}
// create a constructor function called "Car"
// car takes an options object as its only argument
// your options object should have "make", "model", "year" properties on it
Expand All @@ -55,10 +86,10 @@ console.log(counter.total());

// 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.
Expand All @@ -75,7 +106,11 @@ while(n >= 1) {
}
// 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.



n = 10;
const countDown = () => {
console.log(n);
n--;
if(n >=1) {countDown();}
};
countDown();