diff --git a/fundamentals/bug-challenge-es6/__tests__/bug-challenge-tests.js b/fundamentals/bug-challenge-es6/__tests__/bug-challenge-tests.js
index 93c9d5480..f4cfcee69 100644
--- a/fundamentals/bug-challenge-es6/__tests__/bug-challenge-tests.js
+++ b/fundamentals/bug-challenge-es6/__tests__/bug-challenge-tests.js
@@ -1,14 +1,15 @@
 import BugChallenge from '../bug-challenge';
 import '../jest-helpers';
 
-const challenge = new BugChallenge();
-
 describe('Bug challenge ES6', () => {
 
+  let challenge;
   beforeEach(() => {
     console.clear();
+    challenge = new BugChallenge();
   });
 
+
   describe('bug1', () => {
 
     it("should list the names and ages of people", () => {
@@ -102,7 +103,7 @@ describe('Bug challenge ES6', () => {
   describe('bug7', () => {
 
     it("should first run with stopOnError=all and then with stopOnError=null", () => {
-      challenge.bug6();
+      challenge.bug7();
 
       expect(console.logs).toEqual([
         'run: stopOnError=all',
diff --git a/fundamentals/bug-challenge-es6/bug-challenge.js b/fundamentals/bug-challenge-es6/bug-challenge.js
index a08418a39..fc09a75b0 100644
--- a/fundamentals/bug-challenge-es6/bug-challenge.js
+++ b/fundamentals/bug-challenge-es6/bug-challenge.js
@@ -41,46 +41,55 @@ export default class BugChallenge {
         age: 40
       }];
 
-      for (let person in people) {
+      for (let person of people) {
         console.log(`${person.name} is ${person.age}`);
       }
     }
-
+    /* bug1: I replace the keyword 'in' within the for loop with 'of' */
+    
     bug2() {
       const array = [1, 2, 3, 4];
-
-      for (let i = 0; i < array.length; i++) {
-        console.log(array.pop());
-      }
+       
+        while (array.length > 0) {
+          console.log(array.pop());
+        }
     }
-
+   /* bug2: I used console log and the functions pop() so that every time the function loops 
+      it prints out the last element in the array. So that it is reversed.*/
+   
     bug3() {
       const array = {};
       array[0] = 'a';
       array[1] = 'b';
       array[2] = 'c';
-
+      
+       
       let total = 0;
-      for (let key in obj) {
-        total += key;
+      for (let key in array) {
+         total += parseInt(key);
       }
 
       console.log(total);
     }
-
+  /* bug3: First I replace the empty curly bracket with an empty square bracket as it is an array.
+           Then I increment the index number of the array and assigned it to the variable total. */
+   
     bug4() {
       // We list all movies, except the top 3.
-      var index = 3;
-      for (index; index < this.top10Movies.length; index++) {
+    
+      for (let index = 3; index < this.top10Movies.length; index++) {
         console.log(`movie: ${this.top10Movies[index]}`);
       }
 
       // We also list all actors, except the top 3.
-      for (index; index < top10Actors.length; index++) {
+      
+      for (let index = 3; index < this.top10Actors.length; index++) {
         console.log(`actor: ${this.top10Actors[index]}`);
       }
     }
-
+   /* bug4: I declared the index variable within both for loop and intialize it with 3. So that we 
+            can eliminate the first 3 movies. */
+   
     bug5() {
       const defaultMethod = 'GET';
       const defaultUseCaching = true;
@@ -88,19 +97,26 @@ export default class BugChallenge {
       function fetch(options) {
         const url = options.url;
         const method = options.method || defaultMethod;
-        const useCaching = options.useCaching || defaultUseCaching;
+        const useCaching = options.useCaching && options.defaultUseCaching ;
 
         console.log(`fetch: ${method} ${url} (useCaching=${useCaching})`);
       }
 
+      
       fetch({
         url: 'http://www.example.com',
-        useCaching: false
-      });
+        useCaching: false,
+      }); 
+
+      
     }
 
+  /* bug5: I deleted the default value for caching on the const 'useCaching'. Although I need more explanation 
+          on this. And I hope I have done the right thing here. */ 
+        
+   
     bug6() {
-      function run(options) {
+      function run(options = {}) {
         if (options.script == undefined) {
           options.script = 'main.js';
         }
@@ -110,28 +126,33 @@ export default class BugChallenge {
 
       run();
     }
-
+  /* bug6: I have declared the script property within the parameter and as an empty bracket. 
+           So it is undefined which meets the if statement.*/
+   
     bug7() {
       function run(options = {}) {
-        if (options.stopOnError == undefined) {
+        if (options.stopOnError === undefined) {
           options.stopOnError = 'all';
-        }
-
-        console.log(`run: stopOnError=${options.stopOnError}`);
+        } 
+           console.log(`run: stopOnError=${options.stopOnError}`);
       }
-
+     
       run();
       run({stopOnError: null});
     }
-
-    bug8() {
-      for (var i = 0; i < 5; i++) {
-        setTimeout(function () {
+  /* bug7: The comparison operator inside the if statement must compare for the exact value and
+       type '===' inorder to run the second callback*/
+   
+     bug8() {
+      for (let i = 0; i < 5; i++) {
+        setTimeout(() => {
           console.log(i+1);
         }, 100*i);
       }
     }
-
+ /* bug8: I replaced 'var' with the keyword 'let' so that it can be used only with function. And I 
+          also replaced the anonymous function with the arrow function.*/
+   
     bug9() {
       const cars = [{
         make: 'Volvo',
@@ -148,27 +169,34 @@ export default class BugChallenge {
       }];
 
       function findCars(make) {
-        return cars.filter(car => car.make = make);
+        return cars.filter(car =>car.make === make);
       }
 
       for (let bmw of findCars('BMW')) {
         console.log(`${bmw.make} ${bmw.type}`);
       }
     }
-
+  /*bug9: The argument 'BMW' should be equal to the property of the cars.make and not assigned as it 
+  used to print them all as having the same value 'BMW' */ 
+   
     bug10() {
       const command = 'printHelp';
 
       switch (command) {
         case 'printMath':
           console.log(`√9=${Math.sqrt(9)}`);
+          break;
         case 'printHelp':
           console.log('Help');
+          break;
         case 'quit':
           console.log('Quitting');
+          break;
       }
     }
-
+ /* bug10: The original code doesn't have the keyword 'break;' and the exection would go continously.
+          I add the keyword 'break' so that the exection can stop when a match is found.*/
+    
     bug11() {
       class Game {
         constructor() {
@@ -176,8 +204,8 @@ export default class BugChallenge {
         }
 
         addPlayers(names) {
-          names.forEach(function (name) {
-            this.players.push({name, points: 0});
+          names.forEach((name) => {
+             this.players.push({name, points: 0});
           });
         }
       }
@@ -189,13 +217,15 @@ export default class BugChallenge {
         console.log(`Player ${player.name} has ${player.points} points`);
       }
     }
-
+ /* bug11:  this.players fails, because the function’s this is undefined, outside the function. 
+             Adding the arrow function lets you to use the player property outside.   */   
+    
     bug12() {
       let y = 5;
 
       function printVector() {
         let x = 6;
-            y = 7;
+        let y = 7;
 
         console.log(`Printing vector at (${x}, ${y})`);
       }
@@ -203,35 +233,48 @@ export default class BugChallenge {
       printVector();
       console.log(`y=${y}`);
     }
-
+ /* bug12: I added the keyword let for the value 7 so that it can only be used within the function. */
+   
     bug13() {
       var notInTop10 = (movieName) => {
-        return !this.top10Movies.indexOf(movieName)
+        return this.top10Movies.indexOf(movieName) === -1
       }
       console.log('Independence Day is ' + (notInTop10('Independence Day')?'not ':'') + 'in the top 10!');
       console.log('AI is ' + (notInTop10('AI')?'not ':'') + 'in the top 10!');
       console.log('Godfather is ' + (notInTop10('Godfather')?'not ':'') + 'in the top 10!');
       console.log('Inception is ' + (notInTop10('Inception')?'not ':'') + 'in the top 10!');
     }
+  /* bug13: The index of the first occurrence of the specified value if not found is -1. If the index is 
+            not found that means it index is equal to -1 and prints out as not found within the top 10.  */ 
+    
     bug14() {
-
-      console.log('AI is ' + (isInFirstPlace('AI')?'':'not ') + 'best movie ever')
-      console.log('Godfather is ' + (isInFirstPlace('Godfather')?'':'not ') + 'best movie ever')
       var isInFirstPlace = (movieName) => {
         return this.top10Movies[0] === movieName
-      }
+      }  
+         console.log('AI is ' + (isInFirstPlace('AI')?'':'not ') + 'best movie ever');
+         console.log('Godfather is ' + (isInFirstPlace('Godfather')?'':'not ') + 'best movie ever');
+      
     }
+    /* bug14:Putting the console.log statements after the function declaration solved the problem. That is 
+             because functions are hoisted up, and variables are not (only their declaration is).*/
+    
     bug15() {
-      var getAlphabeticalFirst = function() {
-        return this.top10Actors.sort()[0]
+      var getAlphabeticalFirst = () => {
+        return this.top10Actors.sort()[0];
       }
 
       console.log(`The first actor when sorted alphabetically is ${getAlphabeticalFirst()}`)
     }
+    /* bug15: using an arrow function makes sure that whatever is `this` outside of the function, is 
+        also `this` inside the function. If you use `function`, the function will have a very different 
+        `this`. That's one of the advantages of using the arrow functions.*/
+
     bug16() {
       const ranking = this.top10Actors.indexOf('Al Pacino');
-      // var thirdRankedActor = this.top10Actors['2'];
-      console.log(`Al Pacino is ranked ${ranking + '1'}`)
+      console.log(`Al Pacino is ranked ${ranking + 1}`)
     }
 
+    /* bug16: Before the number 1 was within a string so it was concatenated. The result was '31'.
+              Now it is adding the index of the passed parameter(3) and adding 1 to return 4. 
+        */
 }