Document Dom

<!DOCTYPE html>
<html>
<body>
  <a href="https://www.closetag.com/tutorial/html">HTML</a><br>
  <a href="https://www.closetag.com/tutorial/html">CSS</a>
  <p>Click the button to display the URL of the first link (index 0) in the document.</p>
  <button id="button">Try it</button>
  <p id="demo"></p>
  <script>
    let button = document.getElementById('button');
    let links = document.links[0].href; 
    let result = document.getElementById('demo');
    button.addEventListener("click",()=>{
    result.innerHTML = links;
    });
  </script>
</body>
</html>