未命名 JdR724

            
            <button>+1</button>
<span></span>

<style>
  button {
    background-color: skyblue;
    border-radius: 1rem;
  }
</style>

<script>
  const el = document.querySelector("button");
  el.addEventListener('click', add);

  let counter = 0;

  function add() {
    counter = counter + 1;
    document.querySelector("span").textContent = counter;
  }
</script>