Merge 16d6ffc697 into ca3d16dcce

src/data-structures/doubly-linked-list/DoublyLinkedListNode.js

@@ -1,8 +1,9 @@
 export default class DoublyLinkedListNode {
-  constructor(value, next = null, previous = null) {
-    this.value = value;
-    this.next = next;
-    this.previous = previous;
+  constructor(value, next = null, previous = null) {//create a constructor.
+    
+    this.value = value;//the this keyword is used to refer to the object being created pretty much like a memory locatin
+    this.next = next;//this is to store the address of the next node
+    this.previous = previous;//this is to store the address of the previous node
   }
 
   toString(callback) {