class Stack<T> {  private items: T[] = [];  push(item: T): void {    this.items.push(item);  }  pop(): T | undefined {    return this.items.pop();  }  peek(): T | undefined {    return this.items[this.items.length - 1];  }  isEmpty(): boolean {    return this.items.length === 0;  }  size(): number {    return this.items.length;  }  clear(): void {    this.items = [];  }  toArray(): T[] {    return [...this.items];  }}export default Stack;

import Stack from './Stack';const stack = new Stack<number>();stack.push(10);stack.push(20);stack.push(30);console.log('Size:', stack.size());console.log('Peek:', stack.peek());while (!stack.isEmpty()) {  console.log('Popped:', stack.pop());}