Steps:

  • Stack has methods add, remove, peek, size, clear
class Stack {
    constructor() {
        this.items = [];
    }

    add(element) {
        this.items.push(element);
    }

    remove() {
        if(this.items.length > 0) {
            return this.items.pop();
        }
    }

    peek() {
        return this.items[this.items.length - 1];
    }

    size() {
        return this.items.length;
    }

    clear() {
        this.items = [];
    }
}

let s = new Stack();
s.add(2);
s.add(3);
s.size();
s.items;
s.remove();
s.peek();
s.items;
s.clear();
s.items;

References: