cards-and-button.js

import React from 'react';
import { useGlobal } from 'reactn';
import { getRandomCard } from './utils';
import Card from './card';

const Cards = () => {
  const [cards, setCards] = useGlobal('cards');
  return (
    <div>
      {cards.map(card => (
        <Card key={card} card={card} />))}

      <button
        onClick={() => setCards(getRandomCard(cards))}
      >Get another</button>
    </div>
  );
};

export default Cards;