class Queue { constructor() { this.queue = []; } enqueue(item) { return this.queue.unshift(item); } dequeue() { return this.queue.pop(); } peek() { return this.queue[this.length - 1]; } get length() { return this.queue.length; } isEmpty() { return this.queue.length === 0; } } const queue = new Queue(); queue.enqueue(1); queue.enqueue(2); console.log(queue); queue.dequeue(); console.log(queue);