added CircularLinkedList class in ES6 syntax

Author: loiane

chapter05/05-CircularLinkedList2.js

@@ -56,12 +56,12 @@ let CircularLinkedList2 = (function () {
                     previous,
                     index = 0;
 
-                if (position === 0) { //add on first position
+              if (position === 0) { //add on first position
 
                     node.next = current;
 
                     //update last element
-                    while (current.next !== head) { //last element will be head instead of NULL
+                    while (current.next !== this.getHead()) { //last element will be head instead of NULL
                         current = current.next;
                     }
 
@@ -101,7 +101,7 @@ let CircularLinkedList2 = (function () {
                 //removing first item
                 if (position === 0) {
 
-                    while (current.next !== head) { //needs to update last element first
+                    while (current.next !== this.getHead()) { //needs to update last element first
                         current = current.next;
                     }
 

chapter05/06-UsingCircularLinkedList.js

@@ -1,6 +1,6 @@
 let circularLinkedList = new CircularLinkedList2();
 
-/*circularLinkedList.append(15);
+circularLinkedList.append(15);
 circularLinkedList.print();
 
 circularLinkedList.append(16);
@@ -25,4 +25,4 @@ circularLinkedList.removeAt(2);
 circularLinkedList.print();
 
 console.log(circularLinkedList.indexOf(14.5));
-console.log(circularLinkedList.indexOf(16));*/
+console.log(circularLinkedList.indexOf(16));