Add elements

<!DOCTYPE html>
<html>
<body>

<p>Click the button to display the name of the button's second attribute (index 1).</p>

<button id="myBtn" onclick="myFunction()">Try it</button>

<p><strong>Note:</strong> In Internet Explorer 8 and earlier, the attributes property will return a collection of all possible attributes for the element, and will, in this example, display the name of a different attribute.</p>

<p id="demo"></p>

<script>
function myFunction() {
  var x = document.getElementById("myBtn").attributes[1].name;
  document.getElementById("demo").innerHTML = x;
}
</script>

</body>
</html>