queue.js

class Queue {
  constructor() {
    this._items = [];
  }

  enqueue(element) {
    if (Array.isArray(element)) {
      this._items.push(...element);
    } else {
      this._items.push(element);
    }
  }

  dequeue() {
    return this._items.shift();
  }

  front() {
    return this._items[0];
  }

  isEmpty() {
    return this._items.length === 0;
  }

  get size() {
    return this._items.length;
  }

  clear() {
    return this._items = [];
  }

  print() {
    console.log(this._items.toString());
  }
}