stack.js

class Node {
    constructor(value, next) {
        this.value = value;
        this.next = next;
    }
}

class Stack {
    constructor() {
        this.firstNode = null;
        this.length = 0;
    }

    add(value) {
        const node = new Node(value, this.firstNode)

        this.firstNode = node;
        this.length++;

        return value;
    }

    peek() {
        if (this.firstNode == null) throw new Error('Stack is empty.');

        return this.firstNode.value;
    }

    pop() {
        if (this.firstNode == null) throw new Error('Stack is empty.');

        const node = this.firstNode;
        this.firstNode = node.next;
        this.length--;

        return node.value;
    }

    [Symbol.iterator]() {
        let node = this.firstNode;

        return {
            next() {
                if (node == null) {
                    return {
                        done: true,
                        value: undefined
                    }
                }
                else {
                    const value = node.value;
                    node = node.next;

                    return {
                        done: false,
                        value
                    }
                }

            }
        }
    }
}


const size = 10_000_000;
const s = new Stack();

for (let i = 0; i < size; i++) {
    const value = ~~(Math.random() * 100);
    s.add(value);
    // console.log(value);
}

console.log(`Size: ${s.length}`);

for (let i = 0; i < size; i++) {
    const value = s.pop();
    // console.log(value);
}

console.log(`Size: ${s.length}`);