Linked list addAt method

JavaScript
#1

Tell us what’s happening:
it is passing all test but I am little confused why it not showing in the console when applying this method

Your code so far


function LinkedList() {
var length = 0;
var head = null;

var Node = function(element) {
  this.element = element;
  this.next = null;
};

this.size = function() {
  return length;
};

this.head = function() {
  return head;
};

this.add = function(element) {
  var node = new Node(element);
  if (head === null) {
    head = node;
  } else {
    var currentNode = head;

    while (currentNode.next) {
      currentNode = currentNode.next;
    }

    currentNode.next = node;
  }
  length++;
};

// Only change code below this line
this.addAt = function(index,element) {
  if (index <0 || index >= this.size())
  return false;
  let count = 0 ;
  var current = head ;
  var prev ;
  var node = new Node(element)
    if (index==count){
      head = node
      head.next= current;
      length++;
    } else {
      prev = current.next;
      
      while(current.next ) {
      count++;
      current = current.next;
      // console.log(prev)
      if (index == count){
      current = node;
      }
    }//console.lo
    current.next = prev
    length++;
  
    }
}
    // console.log(current,prev)

// Only change code above this line
}
let exp = new LinkedList() 
exp.add(14)
exp.add(13)
// exp.addAt(0,15)
exp.addAt(1,16)
console.log(exp.head(),exp.size())

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36.

Challenge: Add Elements at a Specific Index in a Linked List

Link to the challenge:

#2