class Stack { constructor() { this.array = []; } peek() { return this.array[this.array.length-1]; } push(value) { this.array.push(value); return this; } pop() { this.array.pop(); } //isEmpty } const myStack = new Stack(); myStack.push("Albert"); myStack.push("Dominik"); myStack.push("Alfred"); myStack.push("Kinga"); myStack.push("Monika"); console.log(myStack); console.log(myStack.peek()); console.log(myStack.pop()); console.log(myStack.peek());