// setAttribute
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Properties</title>
<style>
body {
background-color: aquamarine;
}
</style>
</head>
<body>
<div id="box"> This is a div</div>
<p class="para"> This is a paragraph</p>
<script>
let div = document.querySelector("div");
console.log(div);
id = div.setAttribute("id","new box");
console.dir(id);
</script>
</body>
</html>