WhyCan Forum(哇酷开发者社区)

<script>
document.addEventListener("DOMContentLoaded", function(event) {
  /* DOM is ready, so we can query for its elements */
  var dragonHealth = document.getElementById("health").value;
  console.log(dragonHealth);
  
  /*additional code for comment*/
  document.querySelector('button').addEventListener("click", function(event){
    document.getElementById("health").value += 5;
  });
})
</script>

<progress id="health" value="60" max="100"></progress>
<button>change progress value</button>