//adding 'p' tag to body
var tag = document.createElement("p"); // <p></p>
var text = document.createTextNode("TEST TEXT");
tag.appendChild(text); // <p>TEST TEXT</p>
var element = document.getElementsByTagName("body")[0];
element.appendChild(tag); // <body> <p>TEST TEXT</p> </body><html>
<head>
<title>t1</title>
<script type="text/javascript">
function addNode()
{var newP = document.createElement("p");
var textNode = document.createTextNode(" This is a new text node");
newP.appendChild(textNode);
document.getElementById("firstP").appendChild(newP); }
</script> </head>
<body> <p id="firstP">firstP<p> </body>
</html>
const set = new Set([1, 2]);
console.log(set.values());
// adding new elements
set.add(3);
console.log(set.values());
// adding duplicate elements
// does not add to Set
set.add(1);
console.log(set.values());