Remove head

Author: dhimasanb

linkedList.js

@@ -23,11 +23,20 @@ LinkedList.prototype.addToTail = function(value) {
   this.tail = newNode;
 }
 
-let myLL = new LinkedList();
+LinkedList.prototype.removeHead = function() {
+  if(!this.head) return null;
+  let val = this.head.value;
+  this.head = this.head.next;
+  if(this.head) this.head.prev = null;
+  else this.tail = null;
+  return val;
+}
+
+let ll = new LinkedList();
 
-myLL.addToTail(10);
-myLL.addToTail(20);
-myLL.addToTail(30);
-myLL.addToHead(100);
+ll.addToHead(1000);
+ll.addToHead(2000);
+ll.addToTail(3000);
 
-console.log(myLL.tail.prev.prev.prev);
+ll.removeHead();
+console.log(ll.removeHead());