Linked List 구현

class LinkedList {
  constructor(value) {
      this.head = {
          value: value,
          next: null
      };
      this.tail = this.head;
      this.length = 1;
  }
  append(value) {
    const newNode = {
      value: value,
      next: null
    }
    console.log(newNode)
    this.tail.next = newNode;
    this.tail = newNode;
    this.length++;
    return this;
  }
  prepend(value) {
    const newNode = {
      value: value,
      next: null
    }
    newNode.next = this.head;
    this.head = newNode;
    this.length++;
    return this;
  }
  printList() {
    const array = [];
    let currentNode = this.head;
    while(currentNode !== null){
        array.push(currentNode.value)
        currentNode = currentNode.next
    }
    return array;
  }
  insert(index, value){
    if(index >= this.length) {
      console.log('yes')
      return this.append(value);
    }
    
    const newNode = {
      value: value,
      next: null
    }
    const leader = this.traverseToIndex(index-1);
    const holdingPointer = leader.next;
    leader.next = newNode;
    newNode.next = holdingPointer;
    this.length++;
    return this.printList();
  }
  traverseToIndex(index) {
    let counter = 0;
    let currentNode = this.head;
    while(counter !== index){
      currentNode = currentNode.next;
      counter++;
    }
    return currentNode;
  }
  remove(index) {
    const leader = this.traverseToIndex(index-1);
    const unwantedNode = leader.next;
    leader.next = unwantedNode.next;
    this.length--;
    return this.printList();
  }
  reverse() {
    if (!this.head.next) return this.head;
    let first = this.head;
    this.tail = this.head;
    let second = first.next;
    while(second) {
      const temp = second.next;
      second.next = first;
      first = second;
      second = temp;
    }
    this.head.next = null;
    this.head = first;
    return this.printList()
  }
}