Queue Data Structure in JavaScript

let myArray = [1, 2, 3, 4, 5, 6, 7, 8, 9];

class Queue{
    constructor() {

        this.items=[]

    }

    enqueue(element) {

        this.items.push(element)
    }

    dequeue() {

        if (this.items.length == 0) {

            return `Queue is empty`;
        }

        return this.items.shift()
    }

    peek() {
       
        if (this.items.length == 0) {

            return `Queue is empty`;
        }

        return this.items[0]
        
    }

    getSize() {

        return this.items.length;
    }

    isEmpty() {

        if (this.items.length == 0) {
            return true
        }

        return false
    }
}

const queue = new Queue()
queue.enqueue(50)
queue.enqueue(200)
queue.enqueue(500)
console.log(queue.dequeue());
console.log(queue.peek());
console.log(queue.getSize());
console.log(queue.isEmpty());